LC87BK00 SERIES USER'S MANUAL

CMOS 8-BIT MICROCONTROLLER
LC87BK00 SERIES
USER’S MANUAL
http://onsemi.com
REV : 1.00
ON Semiconductor
Digital Solution Division
Microcontroller & Flash Business Unit
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Contents
Chapter 1
1.1
1.2
1.3
1.4
1.5
1.6
1.7
1.8
1.9
1.10
Overview ··················································································· 1-1
Features ···················································································· 1-1
Pin Assginment ··········································································· 1-6
System Block Diagram ·································································· 1-7
Pin Functions ·············································································· 1-8
On-chip Debugger Pin Connection Requirements ····························· 1-10
Recommended Unused Pin Connections ········································ 1-10
Port Output Types ······································································ 1-10
User Option Table ······································································ 1-11
Power Pin Treatment Recommendations (VDD1, VSS1) ···················· 1-11
Chapter 2
2.1
2.2
2.3
2.4
2.5
2.6
2.7
2.8
2.9
2.10
2.11
Overview
Internal Configuration
Memory Space ············································································ 2-1
Program Counter (PC) ·································································· 2-1
Program Memory (ROM) ······························································· 2-2
Internal Data Memory (RAM)·························································· 2-2
Accumulator/A Register (ACC/A) ···················································· 2-3
B Register (B) ············································································· 2-3
C Register (C) ············································································· 2-4
Program Status Word (PSW) ························································· 2-4
Stack Pointer (SP) ······································································· 2-5
Indirect Addressing Registers························································· 2-5
Addressing Modes ······································································· 2-6
2.11.1
Immediate Addressing (#) ································································· 2-6
2.11.2
Indirect Register Indirect Addressing ([Rn]) ·········································· 2-7
2.11.3
Indirect Register + C Register Indirect Addressing ([Rn, C]) ····················· 2-7
2.11.4
Indirect Register (R0) + Offset Value Indirect Addressing ([off])
··················································································· 2-8
2.11.5
Direct Addressing (dst) ···································································· 2-8
2.11.6
ROM Table Look-up Addressing ························································ 2-9
2.11.7
External Data Memory Addressing ····················································· 2-9
2.12 Wait Operation ·········································································· 2-10
2.12.1
Occurrence of a Wait Operation ························································ 2-10
2.12.2
What is a Wait Operation? ······························································· 2-10
Chapter 3
3.1
Peripheral System Configuration
Port 0 ························································································ 3-1
3.1.1
Overview ························································································ 3-1
－1－
Contents
3.1.2
Functions ························································································ 3-1
3.1.3
Related Registers ············································································· 3-2
3.1.4
Options ·························································································· 3-4
3.1.5
HALT and HOLD Mode Operation ························································ 3-4
3.2
Port 1 ························································································ 3-5
3.2.1
Overview ························································································ 3-5
3.2.2
Functions ························································································ 3-5
3.2.3
Related Registers ············································································· 3-6
3.2.4
Options ························································································· 3-12
3.2.5
HALT and HOLD Mode Operation ······················································· 3-12
3.3
Port 2 ······················································································ 3-13
3.3.1
Overview ······················································································· 3-13
3.3.2
Functions ······················································································· 3-13
3.3.3
Related Registers ············································································ 3-14
3.3.4
Options ························································································· 3-16
3.3.5
HALT and HOLD Mode Operation ······················································· 3-16
3.4
Port 7 ······················································································ 3-17
3.4.1
Overview ······················································································· 3-17
3.4.2
Functions ······················································································· 3-17
3.4.3
Related Registers ············································································ 3-18
3.4.4
Options ························································································· 3-22
3.4.5
HALT and HOLD Mode Operation ······················································· 3-22
3.5
Timer/Counter 0 (T0) ·································································· 3-23
3.5.1
Overview ······················································································· 3-23
3.5.2
Functions ······················································································· 3-23
3.5.3
Circuit Configuration ········································································ 3-24
3.5.4
Related Registers ············································································ 3-29
3.6
Timer/Counter 1 (T1) ·································································· 3-32
3.6.1
Overview ······················································································· 3-32
3.6.2
Functions ······················································································· 3-32
3.6.3
Circuit Configuration ········································································ 3-34
3.6.4
Related Registers ············································································ 3-39
3.7
Timers 6 and 7 (T6, T7) ······························································ 3-44
3.7.1
Overview ······················································································· 3-44
3.7.2
Functions ······················································································· 3-44
3.7.3
Circuit Configuration ········································································ 3-44
3.7.4
Related Registers ············································································ 3-47
3.8
Base Timer (BT) ········································································ 3-49
3.8.1
Overview ······················································································· 3-49
3.8.2
Functions ······················································································· 3-49
－2－
Contents
3.8.3
Circuit Configuration ········································································ 3-50
3.8.4
Related Registers ············································································ 3-51
3.9
Serial Interface 1 (SIO1)······························································ 3-53
3.9.1
Overview ······················································································· 3-53
3.9.2
Functions ······················································································· 3-53
3.9.3
Circuit Configuration ········································································ 3-54
3.9.4
SIO1 Communication Examples ························································ 3-58
3.9.5
Related Registers ·········································································· 3-62
3.10 AD Converter (ADC12) ······························································· 3-65
3.10.1
Overview······················································································ 3-65
3.10.2
Functions ····················································································· 3-65
3.10.3
Circuit Configuration ······································································· 3-66
3.10.4
Related Registers ·········································································· 3-66
3.10.5
AD Conversion Example ································································· 3-70
3.10.6
Hints on the Use of the ADC ··························································· 3-71
Chapter 4
4.1
Control Functions
Interrupt Function ········································································ 4-1
4.1.1
Overview ························································································ 4-1
4.1.2
Functions ························································································ 4-1
4.1.3
Circuit Configuration ········································································· 4-2
4.1.4
Related Registers ············································································· 4-3
4.2
System Clock Generator Function ··················································· 4-5
4.2.1
Overview ························································································ 4-5
4.2.2
Functions ························································································ 4-5
4.2.3
Circuit Configuration ········································································· 4-6
4.2.4
Related Registers ············································································· 4-8
4.2.5
Example of Switching the CF Oscillation Amplifier Size ··························· 4-13
4.3
Standby Function······································································· 4-14
4.3.1
Overview ······················································································· 4-14
4.3.2
Functions ······················································································· 4-14
4.3.3
Related Register ············································································· 4-15
4.4
Reset Function ·········································································· 4-20
4.4.1
Overview ······················································································· 4-20
4.4.2
Functions ······················································································· 4-20
4.4.3
Reset State ···················································································· 4-21
4.5
Watchdog Timer (WDT) ······························································ 4-22
4.5.1
Overview ······················································································· 4-22
4.5.2
Functions ······················································································· 4-22
4.5.3
Circuit Configuration ········································································ 4-23
－3－
Contents
4.5.4
Related Register ············································································· 4-25
4.5.5
Using the Watchdog Timer ································································ 4-27
4.5.6
Notes on the Use of the Watchdog Timer ················································ 4-28
4.6
Internal Reset Function ······························································· 4-29
4.6.1
Overview ······················································································· 4-29
4.6.2
Functions ······················································································· 4-29
4.6.3
Circuit Configuration ········································································ 4-29
4.6.4
Options··················································································4-30
4.6.5
Sample Operating Waveforms of the Internal Reset Circuit ······················ 4-32
4.6.6
Notes on the Use of the Internal Reset Circuit ······································· 4-33
4.6.7
Notes to be Taken When Not Using the Internal Reset Circuit ·················· 4-35
Appendixes
Appendix-I Special Function Register (SFR) Map ······························· AI-(1-7)
Appendix-II Port Block Diagrams ···················································· AII-(1-6)
Appendix-III
LC872000/LC87B000 Series On-chip Debugger Pin Treatment Guide
···················································· AIII-(1-2)
－4－
LC87BK00 Chapter 1
1. Overview
1.1 Overview
The LC87BK00 series is an 8-bit microcontroller that, centered around a CPU running at a minimum bus
cycle time of 83.3 ns, integrates on a single chip a number of hardware features such as 8K-byte flash
ROM (onboard programmable) or 8K/6K/4K-byte mask ROM, 256-byte RAM, an on-chip debugger
function (flash ROM version only), a sophisticated 16-bit timer/counter (may be divided into 8-bit timers),
a 16-bit timer/counter (may be divided into 8-bit timers or 8-bit PWMs), two 8-bit timers with a prescaler,
a base timer serving as a time-of-day clock, an asynchronous/synchronous SIO interface, a 12-bit 8channel AD converter with 12-/8-bit resolution selector, a system clock frequency divider, an internal
reset circuit, and 15-source 9-vector interrupt function.
1.2 Features
●
ROM
• Flash ROM version
LC87FBK08A: 8192  8 bits
• Capable of onboard programming with a wide supply voltage range of 2.7 to 5.5V
• 128-byte block erase possible
• Can be written in units of two bytes
• Mask ROM version
LC87BK08A: 8192  8 bits
LC87BK06A: 6144  8 bits
LC87BK04A: 4096  8 bits
●
RAM
• Flash ROM version
LC87FBK08A: 256  9 bits
• Mask ROM version
LC87BK08A: 256  9 bits
LC87BK06A: 256  9 bits
LC87BK04A: 256  9 bits
●
Minimum bus cycle time
• 83.3 ns (12MHz, VDD=2.7 to 5.5V)
Note: The bus cycle time here refers to the ROM read speed.
●
Minimum instruction cycle time (Tcyc)
• 250 ns (12MHz, VDD = 2.7 to 5.5V)
●
Ports
• Normal withstand voltage I/O ports
Ports whose I/O direction can be designated in 1-bit units:
Ports whose I/O direction can be designated in 4-bit units:
• Normal withstand voltage input port:
• Reset pin:
• Power pins:
1-1
12 (P1n, P20, P21, P70, CF2/XT2)
8 (P0n)
1 (CF1/XT1)
1 (RES)
2 (VSS1, VDD1)
●
Timers
• Timer 0: 16-bit timer/counter with a capture register
Mode 0: 8-bit timer with an 8-bit programmable prescaler (with an 8-bit capture register) × 2 channels
Mode 1: 8-bit timer with an 8-bit programmable prescaler (with an 8-bit capture register) + 8-bit
counter (with an 8-bit capture register)
Mode 2: 16-bit timer with an 8-bit programmable prescaler (with a 16-bit capture register)
Mode 3: 16-bit counter (with a 16-bit capture register)
• Timer 1: 16-bit timer/counter that supports PWM/toggle output
Mode 0: 8-bit timer with an 8-bit prescaler (with toggle output) + 8-bit timer/counter with an 8-bit
prescaler (with toggle output)
Mode 1: 8-bit PWM with an 8-bit prescaler × 2 channels
Mode 2: 16-bit timer/counter with an 8-bit prescaler (with toggle output) (Toggle output also possible
from the low-order 8 bits.)
Mode 3: 16-bit timer with an 8-bit prescaler (with toggle output) (The low-order 8 bits can be used as a
PWM module.)
• Timer 6: 8-bit timer with a 6-bit prescaler (with toggle output)
• Timer 7: 8-bit timer with a 6-bit prescaler (with toggle output)
• Base timer
1) The clock can be selected from the subclock (32.768kHz crystal oscillation), system clock, and
timer 0 prescaler output.
2) Interrupts can be generated at five specified time intervals.
3) The base timer cannot be used when the CF oscillator circuit is selected.
●
Serial interface
• SIO1: 8-bit asynchronous/synchronous serial interface
Mode 0: Synchronous 8-bit serial I/O (2- or 3-wire system, 2 to 512 Tcyc transfer clock)
Mode 1: Asynchronous serial I/O (half-duplex, 8 data bits, 1 stop bit, 8 to 2048Tcyc baudrate)
Mode 2: Bus mode 1 (start bit, 8 data bits, 2 to 512 Tcyc transfer clock)
Mode 3: Bus mode 2 (start detection, 8 data bits, stop detection)
●
AD converter: 12 bits 8 channels
• 12-/8-bit AD converter resolution selectable
●
Remote control receiver circuit (multiplexed with P15/SCK1/INT3/T0IN pin)
• Noise rejection function (noise filter time constant selectable from 1Tcyc/32Tcyc/128Tcyc)
●
Clock output function
1) Capable of generating a clock with a frequency of
oscillator clock selected as the system clock.
1
1,
1
2
,
1
4
,
1
8
,
1
16
,
1
32
, or
1
64
of the source
2) Capable of generating a source oscillator clock for the subclock.
●
Watchdog timer
• Capable of generating an internal reset on an overflow of a timer that runs on either the low-speed RC
oscillator clock or subclock.
• Operation when the CPU enters standby mode can be selected from three modes (continue count
operation, stop operation, and stop count operation while retaining the count value).
1-2
LC87BK00 Chapter 1
●
Interrupts
●
15 sources, 9 vector addresses
1) Provides three levels (low (L), high (H), and highest (X)) of multiplex interrupt control. Any
interrupt request of the level equal to or lower than the current interrupt is not accepted.
2) When interrupt requests to two or more vector addresses occur at the same time, the interrupt of
the highest level takes precedence over the other interrupts. For interrupts of the same level, the
interrupt with the lowest vector address has priority.
No.
1
2
3
4
5
6
7
8
9
10
Vector
00003H
0000BH
00013H
0001BH
00023H
0002BH
00033H
0003BH
00043H
0004BH
Level
X or L
X or L
H or L
H or L
H or L
H or L
H or L
H or L
H or L
H or L
Interrupt Source
INT0
INT1
INT2/T0L/INT4
INT3/ base timer
T0H
T1L/T1H
None
SIO1
ADC/T6/T7
Port 0
• Priority level: X > H > L
• When interrupts of the same level occur at the same time, an interrupt with the lowest vector
address is processed first.
●
Subroutine stack level: Up to 128 levels (The stack is allocated in RAM.)
●
High-speed multiplication/division instructions
•
•
•
•
●
16 bits  8 bits
24 bits  16 bits
16 bits  8 bits
24 bits  16 bits
(5 Tcyc execution time)
(12 Tcyc execution time)
(8 Tcyc execution time)
(12 Tcyc execution time)
Oscillator circuits
●
Internal oscillator circuits
1) Low-speed RC oscillator circuit: For system clock (100kHz)
2) Medium-speed RC oscillator circuit: For system clock (1MHz)
3) Multifrequency RC oscillator circuit: For system clock (8MHz)
●
External oscillator circuits
1) High-speed CF oscillator circuit: For system clock, with internal Rf
2) Low-speed crystal oscillator circuit: For low-speed system clock, with internal Rf
<1> The CF oscillator circuit and the crystal oscillator circuit use the same pin, the selection of
which is programmable.
<2> Both the CF and crystal oscillator circuits are stopped while the system reset sequence is in
progress. Since they remain suspended after the reset is released, they must be started under
program control.
●
System clock frequency division function
• Low power consumption operation is possible.
• The minimum instruction cycle can be selected from among 300ns, 600ns, 1.2μs, 2.4μs, 4.8μs, 9.6μs,
19.2μs, 38.4μs, and 76.8μs (at a main clock rate of 10MHz).
1-3
●
Internal reset circuit
●
Power-on reset (POR) function
1) POR reset is generated only when power is turned on.
2) The POR release level can be selected from 4 levels (2.57V, 2.87V, 3.86V, and 4.35V) by
setting options.
●
Low voltage detection reset (LVD) function
1) LVD and POR functions are combined to generate reset when power is turned on and when
power voltage falls below a certain level.
2) The use/non-use of the LVD function and the low voltage detection level (3 levels: 2.81V,
3.79V, 4.28V) can be selected by setting options.
●
Standby function
●
HALT mode: Halts instruction execution while allowing the peripheral circuits to continue operation.
1) Oscillators do not stopped automatically.
2) There are four ways of releasing HALT mode.
<1> Low level input to the reset pin
<2> Generating a reset by low voltage detection
<3> Generating a reset by the watchdog timer
<4> Generating an interrupt
●
HOLD mode: Suspends instruction execution and operation of the peripheral circuits.
1) The CF oscillator, low-speed/medium-speed/multifrequency RC oscillators, and crystal oscillator
automatically stop operation.
Note: The low-speed RC oscillation is also controlled directly by the watchdog timer. Its
oscillation in the standby mode is also controlled by the watchdog timer.
2) There are five ways of releasing HOLD mode.
<1> Low level input to the reset pin
<2> Generating a reset by low voltage detection
<3> Generating a reset by the watchdog timer
<4> Establishing an interrupt source at least at one of INT0, INT1, INT2, and INT4 pins
* INT0 and INT1 HOLD mode release is available only when level detection is set.
<5> Establishing an interrupt source at port 0
●
X'tal HOLD mode: Suspends instruction execution and the operation of the peripheral circuits except
the base timer (when X'tal oscillator is selected).
1) The CF, low-speed/medium-speed/multifrequency RC oscillators automatically stop operation.
Note: The low-speed RC oscillation is also controlled directly by the watchdog timer. Its
oscillation in the standby mode is also controlled by the watchdog timer.
2) The state of crystal oscillation established when X'tal HOLD mode is entered is retained.
3) There are six ways of releasing X'tal HOLD mode.
<1> Low level input to the reset pin
<2> Generating a reset by low voltage detection
<3> Generating a reset by the watchdog timer
<4> Establishing an interrupt source at least at one of INT0, INT1, INT2, and INT4 pins.
* INT0 and INT1 X'tal HOLD mode release is available only when level detection is set.
<5> Establishing an interrupt source at port 0
<6> Establishing an interrupt source in the base timer circuit
Note: Available only when X’tal oscillation is selected.
1-4
LC87BK00 Chapter 1
●
On-chip debugger function (flash ROM version only)
Supports software debugging with the microcontroller mounted on the target board.
Software break setting
Stepwise execution of instructions
Real time RAM data monitoring function
All the memory contents can be monitored and rewritten when the program is running.
(Part of the special function register (SFR) data cannot be rewritten.)
• Two channels of on-chip debugger pins are available for compatibility with small pin count devices.
DBGP0(P0), DBGP1(P1)
•
•
•
•
●
Data security function (flash ROM version only)
• Protects the program data stored in flash memory from unauthorized read or copy.
Note: This data security function does not necessarily provide absolute data security.
●
Package form
•
•
•
•
●
MFP24S (300mil) (Lead-free and halogen-free product)
SSOP24 (225mil) (Lead-free and halogen-free product)
SSOP24 (275mil) (Lead-free and halogen-free product) (make-to-order)
VCT24 (3mm  3mm) (Lead-free and halogen-free product) (make-to-order)
Development tools
• On-chip debugger:
●
<1>TCB87 Type B + LC87FBK08A
<2>TCB87 Type C (3-wire cable) + LC87FBK08A
Programming board
Package
MFP24S (300mil)
SSOP24 (225mil)
SSOP24 (275mil)
VCT24 (3mm x 3mm)
Programming Board
W87F2GM
W87F2GS
Make-to-order
W87FBGV
1-5
1.3 Pin Assignment
P70/INT0/T0LCP/AN8
1
24
P07/T7O/DBGP02
RES#
2
23
P06/AN6/T6O/DBGP01
VSS1
3
22
P05/AN5/CKO/DBGP00
CF1/XT1
4
21
P04/AN4
CF2/XT2
5
20
P03/AN3
VDD1
6
19
P02/AN2
P10
7
18
P01/AN1
P11
8
17
P00/AN0
P12
9
16
P21/INT4/T1IN
P13/SO1/DBGP12
10
15
P20/INT4/T1IN
P14/SI1/SB1/DBGP11
11
14
P17/T1PWMH/BUZ/INT1/T0HCP
P15/SCK1/INT3/T0IN/DBGP10
12
13
P16/T1PWML/INT2/T0IN
TOP VIEW
13 P20/INT4/T1IN
14 P21/INT4/T1IN
15 P00/AN0
16 P01/AN1
17 P02/AN2
18 P03/AN3
SANYO MFP24S (300mil)/SSOP24 (225mil)：(lead-free/halogen-free product)
SSOP24 (275mil)：(lead-free/halogen-free product) (make-to-order)
12 P17/T1PWMH/BUZ/INT1/T0HCP
P04/AN4 19
11 P16/T1PWML/INT2/T0IN
P05/AN5/CKO/DBGP00 20
P06/AN6/T6O/DBGP01 21
10 P15/SCK1/INT3/T0IN/DBGP10
TOP VIEW
9 P14/SI1/SB1/DBGP11
P07/T7O/DBGP02 22
8 P13/SO1/DBGP12
P70/INT0/T0LCP/AN8 23
RES# 24
P11 6
P10 5
VDD1 4
CF2/XT2 3
CF1/XT1 2
VSS1 1
7 P12
SANYO VCT24 (3mm  3mm)：(lead-free/halogen-free product) (make-to-order)
1-6
LC87BK00 Chapter 1
1.4 System Block Diagram
Interrupt control
IR
Standby control
PLA
Flash ROM
SRC
RC
Clock
generator
CF/
X’tal
PC
MRC
Watchdog
timer
Reset circuit
Reset control
RES＃
ACC
B register
(LVD/POR)
C register
Bus interface
ALU
SIO1
Port 0
Timer 0
Port 1
PSW
Timer 1
Port 2
RAR
Timer 6
Port 7
RAM
Timer 7
ADC
Base timer
INT0 to INT2
INT3 (w/noise filter)
Port 2 INT4
1-7
Stack pointer
On-chip debugger
1.5 Pin Functions
Name
VSS1, VSS2
VDD1
I/O
–
–
Port 0
P00 to P07
I/O
Port 1
P10 to P17
I/O
Description
Power supply pin (–)
Power supply pin (+)
• 8-bit I/O port
• I/O can be specified in 4-bit units.
• Pull-up resistors can be turned on and off in 4-bit units.
• HOLD release input
• Port 0 interrupt input
• Pin functions
P05: System clock output
P06: Timer 6 toggle output
P07: Timer 7 toggle output
P00 (AN0) to P06 (AN6): AD converter input port
P05 (DBGP00) to P07 (DBGP02): On-chip debugger 0 pins
• 8-bit I/O port
• I/O can be specified in 1-bit units.
• Pull-up resistors can be turned on and off in 1-bit units.
• Pin functions
P13: SIO1 data output
P14: SIO1 data input / bus I/O
P15: SIO1 clock I/O / INT3 input (input with noise filter)/timer 0
event input/timer 0H capture input
P16: Timer 1 PWML output/INT2 input/HOLD release input/timer 0
event input/timer 0L capture input
P17: Timer 1 PWMH output/buzzer output/INT1 input/HOLD
release input/timer 0H capture input
P15 (DBGP10) to P13 (DBGP12): On-chip debugger 1 pins
Interrupt acknowledge type
INT1
INT2
INT3
Port 2
P20, P21
I/O
I/O
Rising
Falling
○
○
○
○
○
○
Rising &
Falling

○
○
H level
L level
○
○


Rising
Falling
○
○
Rising &
Falling
○
H level
L level


• 1-bit I/O port
• I/O can be specified.
• Pull-up resistors can be turned on and off.
• Pin functions
P70: INT0 input/HOLD release input/timer 0L capture input
P70 (AN8): AD converter input port
Interrupt acknowledge type
INT0
Rising
Falling
○
○
Rising &
Falling

No
Yes
Yes


• 2-bit I/O port
• I/O can be specified in 1-bit units.
• Pull-up resistors can be turned on and off in 1-bit units.
• Pin functions
P20, P21: INT4 input/HOLD release input/timer 1 event input/
timer 0L capture input/timer 0H capture input
Interrupt acknowledge type
INT4
Port 7
P70
Option
No
Yes
No
H level
L level
○
○
Continued on next page.
1-8
LC87BK00 Chapter 1
Continued from preceding page
Name
I/O
Description
I/O
RES
External reset input/internal reset output
• Ceramic resonator/32.768 kHz crystal resonator input
Ｉ
CF1/XT1
• Pin functions
General-purpose input port
• Ceramic resonator /32.768 kHz crystal resonator output
I/O
CF2/XT2
• Pin functions
General-purpose I/O port
1-9
Option
No
No
No
1.6 On-chip Debugger Pin Connection Requirements
For the treatment of the on-chip debugger pins, refer to the separately available documents entitled "RD87
On-chip Debugger Installation Manual" and Appendix-III "LC872000/LC87B000 Series On-chip Debugger
Pin Processing."
1.7 Recommended Unused Pin Connections
Pin Name
P00 to P07
P10 to P17
P20 to P21
P70
CF1/XT1
CF2/XT2
Recommended Unused Pin Connections
Board
Software
Open
Output low
Open
Output low
Open
Output low
Open
Output low
Pulled down with a resistor of 100kΩ or less
General-purpose input port
Pulled down with a resistor of 100kΩ or less
General-purpose input port
1.8 Port Output Types
The table below lists the types of port outputs and the presence/absence of a pull-up resistor.
Data can be read into any input port even if it is in the output mode.
Port
P00 to P07
Option
Selected in
Units of
1 bit
Option
Type
Output Type
1
2
1
2
No
No
Pull-up Resistor
CMOS
Programmable (Note 1)
N-channel open drain
No
P10 to P17
1 bit
CMOS
Programmable
P20, P21
N-channel open drain
Programmable
P70
－
N-channel open drain
Programmable
Ceramic resonator /32.768 kHz
No
CF2/XT2
－
crystal resonator output
N-channel open drain
(N-channel open drain when
selected as general-purpose I/O port)
Note 1: The control of the presence or absence of the programmable pull-up resistors for port 0 and switching
between low- and high-impedance pull-up connections is exercised in nibble (4-bit) units (P00 to P03 or
P04 to P07).
1-10
LC87BK00 Chapter 1
1.9 User Option Table
Option
Port output
type
Option to be
Applied on
Mask
Flash-ROM Option Selected
Version
in Units of
Version *1
P00 to P07
○
○
1 bit
P10 to P17
○
○
1 bit
P20 to P21
○
○
1 bit
×
○

Option Selection
CMOS
N-channel open drain
CMOS
N-channel open drain
CMOS
N-channel open drain
00000H
01E00H
Enable: Use
Disable: Non-use
Program start
address

Low voltage
detection reset
function
Detection
function
Detection
level
○
○

○
○

3 levels
Power-on
reset function
Power-on
reset level
○
○

4 levels
*2
*1: Mask option selection: No change is possible after mask is completed.
*2: Program start address of the mask version is 00000H.
1.10
Power Pin Treatment Recommendations (VDD1, VSS1)
Connect bypass capacitors between the VDD1 and VSS1 pins so that the following conditions are satisfied.
• Connect the VDD1 and VSS1 pins and bypass capacitors C1 and C2 using the shortest possible heavy
lead wires, making sure that the impedances between both pins and bypass capacitors are as equal
(L1=L1’, L2=L2’) as possible.
• Connect a large-capacitance capacitor C1 and a small-capacitance capacitor C2 in parallel.
The capacitance of C2 should be approximately 0.1μF.
L2
L1
VSS1
C1
C2
VDD1
L1’
L2’
1-11
1-12
LC87BK00 Chapter 2
2. Internal Configuration
2.1 Memory Space
This series of microcontrollers has the following three types of memory space:
1)
2)
Program memory space:
Internal data memory space:
3)
External data memory space:
Address
3FFFFH
256K bytes (128K bytes × 2 banks)
64K bytes (0000H to FDFFH out of 0000H to FFFFH is shared
with the stack area.)
16M bytes
Address
FFFFFFH
Program memory space
ROM bank 1
128KB
External data memory space
Internal data
memory space
Address
FFFFH
RAM
16MB
Reserved for
system
FF00H
FEFFH
SFR(8-bit)
(some 9-bit)
1FFFFH
FE00H
ROM bank 0
128KB
FDFFH
RAM/Stack
64 KB
(9-bit config)
0000H
00000H
000000H
Note: SFR is the area in which special function registers such as the accumulator are allocated (see
APPENDIX A-I).
Figure 2.1.1. Types of Memory Space
2.2
Program Counter (PC)
The program counter (PC) is made up of 17 bits and a bank flag BNK. The value of BNK determines the
bank. The low-order 17 bits of the PC allows linear access to the 128K ROM space in the current bank.
Normally, the PC advances automatically in the current bank on each execution of an instruction. Bank
switching is accomplished by executing a Return instruction after pushing necessary addresses onto the
stack. When executing a branch or subroutine instruction, when accepting an interrupt, or when a reset is
generated, the value corresponding to each operation is loaded into the PC.
Table 2.2.1 lists the values that are loaded into the PC when the respective operations are performed.
2-1
Table 2.2.1. Values Loaded in the PC
Operation
PC Value
Reset (Note)
BNK Value
00000H
0
01E00H
0
INT0
00003H
0
INT1
0000BH
0
INT2/T0L/INT4
00013H
0
Inter- INT3/Base timer
rupt T0H
0001BH
0
00023H
0
T1L/T1H
0002BH
0
None
00033H
0
SIO1
0003BH
0
ADC/T6/T7
00043H
0
Port 0
0004BH
0
Unconditional branch
instructions
JUMP
a17
PC=a17
Unchanged
BR
r12
PC=PC+2+r12[-2048 to +2047]
Unchanged
Conditional branch
instructions
BE, BNE, DBNZ, DBZ, BZ, BNZ,
BZW, BNZW, BP, BN, BPC
PC=PC+nb+r8[-128 to +127]
nb: Number of instruction bytes
Unchanged
Call instructions
CALL
a17
PC=a17
Unchanged
RCALL
r12
PC=PC+2+r12[-2048 to +2047]
Unchanged
RCALLA
PC=PC+1+Areg[0 to +255]
Unchanged
RET, RETI
PC16 to 08=(SP)
PC07 to 00=(SP-1)
(SP) denotes the contents of RAM
address designated by the value of
the stack pointer SP.
Return instructions
Standard instructions
NOP, MOV, ADD, …
PC=PC+nb
nb: Number of instruction bytes
BNK is set to
bit 8 of
(SP-1).
Unchanged
Note: The reset-time program start address can be selected through a user option in the flash version product.
In the mask version, the program start address is fixed at address 00000H.
2.3
Program Memory (ROM)
This series of microcontrollers has a program memory space of 256K bytes but the size of the ROM that is
actually incorporated varies with the type of microcontroller. The ROM table look-up instruction (LDCW)
can be used to refer all ROM data within the bank. Of the ROM space, the 256 bytes in ROM bank 0
(01F00H to 01FFFH for this series) are reserved as the option area. Consequently, this area is not
available as a program area.
2.4
Internal Data Memory (RAM)
This series of microcontrollers has an internal data memory space of 64K bytes but the size of the RAM
that is actually incorporated varies with the type of the microcontroller. Nine bits are used to access
addresses 0000H to FDFFH of the 128K ROM space and 8 or 9 bits are used to access addresses FE00H
to FFFFH. The 9th bit of RAM is implemented by bit 1 of the PSW and can be read and written.
The 128 bytes of RAM from 0000H to 007FH are paired to form 64 2-byte indirect address registers. The
bit length of these indirect registers is normally 16 bits (8 bits  2). When they are used by the ROM table
look-up instruction (LDCW), however, their bit length is set to 17 bits (9 high-order bits + 8 low-order
bits).
As shown in Figure 2.4.1, the available instructions vary depending on the RAM address. The high
efficiency of the ROM used and a higher execution speed can be attempted using these instructions
properly.
2-2
LC87BK00 Chapter 2
FFFFH
FF00H
FEFFH
FE00H
FDFFH
2000H
1FFFH
Space reserved
for system
*Note: Some registers are 9-bit
SFR space
* 8-bit
RAM/
Stack space
9-bit
0200H
01FFH
0100H
00FFH
0000H
Bit instruction direct (long)
Bit instruction direct (short)
Non-bit instruction direct (long)/indirect,16-bit operation instruction direct/indirect
Non-bit instruction direct (short)
Figure 2.4.1. RAM Addressing Map
When the value of the PC is stored in RAM during the execution of a subroutine call instruction or
interrupt, assuming that SP represents the current value of the stack pointer, the value of BNK and the loworder 8 bits of the (17-bit) PC are stored in RAM address SP + 1 and the high-order 9 bits in SP + 2, after
which SP is set to SP + 2.
2.5
Accumulator/A Register (ACC/A)
The accumulator (ACC), also called the A register, is an 8-bit register that is used for data computation,
transfer, and I/O processing. It is allocated to address FE00H in the internal data memory space and
initialized to 00H on reset.
Address
Initial Value
R/W
Name
BIT7
BIT6
BIT5
BIT4
BIT3
BIT2
BIT1
BIT0
FE00
0000 0000
R/W
AREG
AREG7
AREG6
AREG5
AREG4
AREG3
AREG2
AREG1
AREG0
2.6
B Register (B)
The B register is combined with the ACC to form a 16-bit arithmetic register during the execution of a 16bit arithmetic instruction. During a multiplication or division instruction, the B register is used with the
ACC and C register to store the results of computation. In addition, during an external memory access
instruction (LDX or STX), the B register designates the high-order 8 bits of the 24-bit address.
The B register is allocated to address FE01H of the internal data memory space and initialized to 00H on
reset.
Address
Initial Value
R/W
Name
BIT7
BIT6
BIT5
BIT4
BIT3
BIT2
BIT1
BIT0
FE01
0000 0000
R/W
BREG
BREG7
BREG6
BREG5
BREG4
BREG3
BREG2
BREG1
BREG0
2-3
2.7
C Register (C)
The C register is used with the ACC and B register to store the results of computation during the execution
of a multiplication or division instruction. In addition, during a C register offset indirect instruction, the C
register stores the offset data (-128 to +127) to the contents of an indirect register.
The C register is allocated to address FE02H of the internal data memory space and initialized to 00H on
reset.
Address
Initial Value
R/W
Name
BIT7
BIT6
BIT5
BIT4
BIT3
BIT2
BIT1
BIT0
FE02
0000 0000
R/W
CREG
CREG7
CREG6
CREG5
CREG4
CREG3
CREG2
CREG1
CREG0
2.8
Program Status Word (PSW)
The program status word (PSW) is made up of flags that indicate the status of computation results, a flag
to access the 9th bit of RAM, and a flag to designate the bank during the LDCW instruction.
The PSW is allocated to address FE06H of the internal data memory space and initialized to 00H on reset.
Address
Initial Value
R/W
Name
BIT7
BIT6
BIT5
BIT4
BIT3
BIT2
BIT1
BIT0
FE06
0000 0000
R/W
PSW
CY
AC
PSWB5
PSWB4
LDCBNK
OV
P1
PARITY
CY (bit 7): Carry flag
CY is set (to 1) when a carry occurs as the result of a computation and cleared (to 0) when no carry occurs.
There are following four types of carries:
1)
2)
3)
4)
Carry resulting from an addition
Borrow resulting from a subtraction
Borrow resulting from a comparison
Carry resulting from a rotation
There are some instructions that do not affect this flag at all.
AC (bit 6): Auxiliary carry flag
AC is set (to 1) when a carry or borrow occurs in bit 3 (bit 3 of the high-order byte during a 16-bit
computation) as the result of an addition or subtraction and cleared (to 0) otherwise.
There are some instructions that do not affect this flag at all.
PSWB5, PSWB4 (bits 5, 4): User bits
These bits can be read and written through instructions. They can be used by the user freely.
LDCBNK (bit 3): Bank flag for the table look-up instruction (LDCW)
This bit designates the ROM bank to be specified when reading the program ROM with a table look-up
instruction.
(0: ROM-ADR = 0 to 1FFFF, 1: ROM-ADR = 20000 to 3FFFF)
OV (bit 2): Overflow flag
OV is set (to 1) when an overflow occurs as the result of an arithmetic operation and cleared (to 0)
otherwise. An overflow occurs in the following cases:
1)
2)
When MSB is used as the sign bit and when the result of negative number + negative number or
negative number – positive number is a positive number.
When MSB is used as the sign bit and when the result of positive number + positive number or
positive number – negative number is a negative number.
2-4
LC87BK00 Chapter 2
When the high-order 8 bits of a 16 bits  8 bits multiplication is nonzero.
When the high-order 16 bits of a 24 bits  16 bits multiplication is nonzero.
When the divisor of a division is 0.
3)
4)
5)
There are some instructions that do not affect this flag at all.
P1 (bit 1): RAM bit 8 data flag
P1 is used to manipulate bit 8 of 9-bit internal data RAM (0000H to FDFFH). Its behavior varies
depending on the instruction executed. See Table 2.4.1 for details.
PARITY (bit 0): Parity flag
This bit shows the parity of the accumulator (A register). The parity flag is set (to 1) when there is an odd
number of 1’s in the A register. It is cleared (to 0) when there is an even number of 1’s in the A register.
2.9
Stack Pointer (SP)
LC870000 series microcontrollers can use RAM addresses 0000H to FDFFH as a stack area. The size of
RAM, however, varies depending on the microcontroller type. The SP is 16 bits long and made up of two
registers: SPL (at address FE0AH) and SPH (at address FE0BH). It is initialized to 0000H on reset.
The SP is incremented by 1 before data is saved in stack memory and decremented by 1 after the data is
restored from stack memory.
Address
Initial Value
R/W
Name
BIT7
BIT6
BIT5
BIT4
BIT3
BIT2
BIT1
BIT0
FE0A
0000 0000
R/W
SPL
SP7
SP6
SP5
SP4
SP3
SP2
SP1
SP0
FE0B
0000 0000
R/W
SPH
SP15
SP14
SP13
SP12
SP11
SP10
SP9
SP8
The value of the SP changes as follows:
1)
2)
3)
4)
When the PUSH instruction is executed: SP = SP + 1, RAM (SP) = DATA
When the CALL instruction is executed: SP = SP + 1, RAM (SP) = ROMBANK + ADL
SP = SP + 1, RAM (SP) = ADH
When the POP instruction is executed: DATA = RAM (SP), SP = SP - 1
When the RET instruction is executed: ADH = RAM (SP), SP = SP - 1
ROM BANK + ADL = RAM(SP), SP = SP - 1
2.10 Indirect Addressing Registers
LC870000 series microcontrollers are provided with three addressing schemes ([Rn], [Rn + C], [off])
which use the contents of indirect registers (indirect addressing modes). (See Section 2.11 for the
addressing modes.) These addressing modes use 64 2-byte indirect registers (R0 to R63) allocated to RAM
addresses 0 to 7EH. The indirect registers can also be used as general-purpose registers (e.g., for saving 2byte data). Naturally, these addresses can be used as ordinary RAM (on a 1-byte (9 bits) basis) if they are
not used as indirect registers. R0 to R63 are "system reserved words" to the assembler and need not be
defined by the user.
2-5
Reserved for system
RAM
･
Address
7FH
R63(upper)
7EH
R63(lower)
R63 ＝ 7EH
･
･
・
･
･
・
03H
R1(upper)
02H
R1(lower)
01H
R0(upper)
00H
R0(lower)
R1 = 2
R0 = 0
Figure 2.10.1. Allocation of Indirect Registers
2.11 Addressing Modes
LC870000 series microcontrollers support the following seven addressing modes:
1)
2)
3)
4)
5)
6)
7)
Immediate (Immediate data refers to data whose value has been established at program preparation
(assembly) time.)
Indirect register (Rn) indirect (0 ≦ n ≦ 63)
Indirect register (Rn) + C register indirect (0 ≦ n ≦ 63)
Indirect register (R0) + Offset value indirect
Direct
ROM table look-up
External data memory access
The rest of this section describes these addressing modes.
2.11.1
Immediate Addressing (#)
The immediate addressing mode allows 8-bit (1-byte) or 16-bit (1-word) immediate data to be handled.
Examples are given below.
Examples:
LD
L1: LDW
PUSH
ADD
BE
#12H;
#1234H;
#34H;
#56H;
#78H, L1;
Loads the accumulator with byte data (12H).
Loads the BA register pair with word data (1234H).
Loads the stack with byte data (34H).
Adds byte data (56H) to the accumulator.
Compares byte data (78H) with the accumulator for a branch.
2-6
LC87BK00 Chapter 2
2.11.2
Indirect Register Indirect Addressing ([Rn])
In indirect register indirect addressing mode, it is possible to select one of the indirect registers (R0 to
R63) and use its contents to designate an address in RAM or SFR. When the selected register contains, for
example, "FE02H," it designates the C register.
Examples: When R3 contains "123H" (RAM address 6: 23H, RAM address 7: 01H)
LD
[R3];
Transfers the contents of RAM address 123H to the accumulator.
L1: STW
[R3];
Transfers the contents of BA register pair to RAM address 123H.
PUSH [R3];
Saves the contents of RAM address123H in the stack.
SUB
[R3];
Subtracts the contents of RAM address 123H from the accumulator.
DBZ
[R3], L1;
Decrements the contents of RAM address 123H by 1 and causes a branch if
zero.
2.11.3
Indirect Register + C Register Indirect Addressing ([Rn, C])
In the indirect register + C register indirect addressing mode, the result of adding the contents of one of
the indirect registers (R0 to R63) to the contents of the C register (-128 to +127 with MSB being the sign
bit) designates an address in RAM or SFR. For example, if the selected indirect register contains "FE02H"
and the C register contains "FFH (-1)," the address "B register (FE02H + (-1) = FE01H" is designated.
Examples: When R3 contains "123H" and the C register contains "02H"
LD
[R3, C];
Transfers the contents of RAM address 125H to the accumulator.
L1: STW
[R3, C];
Transfers the contents of the BA register pair to RAM address 125H.
PUSH [R3, C];
Saves the contents of RAM address 125H in the stack.
SUB
[R3, C];
Subtracts the contents of RAM address 125H from the accumulator.
DBZ
[R3, C], L1; Decrements the contents of RAM address 125H by 1 and causes a branch if
zero.
<Notes on this addressing mode >
The internal data memory space is divided into three closed functional areas as explained in Section 2.1,
namely, 1) system reserved area (FF00H to FFFFH), 2) SFR area (FE00H to FEFFH), and 3) RAM/stack
area (0000H to FDFFH). Consequently, it is not possible to point to a different area using the value of the
C register from the basic area designated by the contents of Rn. For example, if the instruction "LD
[R5,C]" is executed when R5 contains "0FDFFH" and the C register contains "1," since the basic area is 3)
RAM/stack area (0000H to FDFFH), the intended address "0FDFFH+1 = 0FE00H" lies outside the basic
area and "0FFH" is consequently placed in the ACC as the result of LD. If the instruction "LD [R5,C]" is
executed when R5 contains "0FEFFH" and the C register contains "2," since the basic area is 2) SFR area
(FE00H to FEFFH), the intended address "0FEFFH+2 = 0FF01H" lies outside the basic area. In this case,
since SFR is confined in an 8-bit address space, the part of the address data addressing outside the 8-bit
address space is ignored and the contents of 0FE01H (B register) are placed in the ACC as the result of the
computation "0FF01H&0FFH+0FE00H = 0FE01H."
2-7
2.11.4
Indirect Register (R0) + Offset Value Indirect Addressing ([off])
In this addressing mode, the results of adding the 7-bit signed offset data off (-64 to + 63) to the contents
of the indirect register R0 designate an address in RAM or SFR. If R0 contains "FE02H" and off has a
value of "7EH(-2)," for example, the A register (FE02H + (-2) = FE00H) is designated.
Examples: When R0 contains "123H" (RAM address 0: 23H, RAM address 1: 01H)
LD
[10H];
Transfers the contents of RAM address 133H to the accumulator.
L1: STW
[10H];
Transfers the contents of the BA register pair to RAM address 133H.
PUSH [10H];
Saves the contents of RAM address 133H in the stack.
SUB
[10H];
Subtracts the contents of RAM address 133H from the accumulator.
DBZ
[10H], L1;
Decrements the contents of RAM address 133H by 1 and causes a branch if
zero.
<Notes on this addressing mode>
The internal data memory space is divided into three closed functional areas as explained in Section 2.1,
namely, 1) system reserved area (FF00H to FFFFH), 2) SFR area (FE00H to FEFFH), and 3) RAM/stack
area (0000H to FDFFH). Consequently, it is not possible to point to a different area using an offset value
from the basic area designated by the contents of R0. For example, if the instruction "LD [1]" is executed
when R0 contains "0FDFFH," since the basic area is 3) RAM/stack area (0000H to FDFFH), the intended
address "0FDFFH+1 = 0FE00H" lies outside the basic area and "0FFH" is placed in the ACC as the result
of LD. If the instruction "LD [2]" is executed when R0 contains "0FEFFH," since the basic area is 2) SFR
area (FE00H to FEFFH), the intended address "0FEFFH+2 = 0FF01H" lies outside the basic area. In this
case, since SFR is confined in an 8-bit address space, the part of the address data addressing outside the 8bit address space is ignored and the contents of 0FE01H (B register) are placed in the ACC as the result of
computation "0FF01H&0FFH+0FE00H = 0FE01H."
2.11.5
Direct Addressing (dst)
Direct addressing mode allows a RAM or SFR address to be specified directly in an operand. In this
addressing mode, the assembler automatically generates the optimum instruction code from the address
specified in the operand (the number of instruction bytes varies according to the address specified in the
operand). Long (middle) range instructions (identified by an "L (M)" at the end of the mnemonic) are
available to make the byte count of instructions constant (align instructions with the longest one).
Examples:
LD
123H;
LDL
123H;
STW
PUSH
SUB
DBZ
123H;
123H;
123H;
123H, L1;
L1:
Transfers the contents of RAM address 123H to the accumulator
(2-byte instruction).
Transfers the contents of RAM address 123H to the accumulator
(3-byte instruction).
Transfers the contents of the BA register pair to RAM address 123H.
Saves the contents of RAM address 123H in the stack.
Subtracts the contents of RAM address 123H from the accumulator.
Decrements the contents of RAM address 123H by 1 and causes a branch if
zero.
2-8
LC87BK00 Chapter 2
2.11.6 ROM Table Look-up Addressing
LC870000 series microcontrollers can read 2-byte data on the ROM into the BA register pair at once using
the LDCW instruction. Three addressing modes [Rn], [Rn, C], and [off] are available for this purpose. (In
this case only, Rn is configured as 17-bit registers (128K-byte space)).
For models with banked ROM, it is possible to reference the ROM data in the ROM bank (128K bytes)
identified by the LDCBNK flag (bit 3) in the PSW. Consequently, when looking into the ROM table on a
series model with banked ROM, execute the LDCW instruction after switching the bank using the SET1
or CLR1 instruction so that the LDCBNK flag designates the ROM bank where the ROM table resides.
Examples:
TBL: DB
DB
DW
•
•
LDW
CHGP3
CHGP1
STW
LDCW
MOV
LDCW
INC
LDCW
34H
12H
5678H
•
•
#TBL;
(TBL >> 17) & 1;
(TBL >> 16) & 1;
R0;
[1];
#1, C;
[R0, C];
C;
[R0, C]:
Loads the BA register pair with the TBL address.
Loads LDCBNＫ in PSW with bit 17 of the TBL address. (Note 1)
Loads P1 in PSW with bit 16 of the TBL address.
Loads indirect register R0 with the TBL address (bits 16 to 0).
Reads the ROM table (B=78H, ACC=12H).
Loads the C register with 01H.
Reads the ROM table (B=78H, ACC=12H).
Increments the C register by 1.
Reads the ROM table (B=56H, ACC=78H).
Note 1: LDCBNK (bit 3) of PSW needs to be set up only for models with banked ROM.
2.11.7
External Data Memory Addressing
LC870000 series microcontrollers can access external data memory spaces of up to 16M bytes (24 bits)
using the LDX and STX instructions. To designate a 24-bit space, specify the contents of the B register (8
bits) as the highest-order byte of the address and the contents (16 bits) of (Rn), (Rn) + (C), or (R0) + off
(either one) as the low-order bytes of the address.
Examples:
LDW
STW
MOV
LDX
#3456H;
R5;
#12H, B;
[1];
Sets up the low-order 16 bits.
Loads the indirect register R5 with the low-order 16 bits of the address.
Sets up the high-order 8 bits of the address.
Transfers the contents of external data memory (address 123456H) to the
accumulator.
2-9
2.12 Wait Operation
2.12.1 Occurrence of a Wait Operation
This series of microcontrollers does not perform a wait operation that automatically suspends execution of
instructions.
2.12.2 What is a Wait Operation?
1)
2)
3)
4)
5)
When a wait request occurs according to the event explained in Subsection 2.12.1, the CPU
suspends the execution of the instruction for one cycle, during which the required data is transferred.
This is called a wait operation.
Peripheral circuits such as timers and PWM continue processing during the wait operation.
A wait operation is not performed 2 cycles or more consecutively.
The microcontroller does not perform a wait operation when it is in HALT or HOLD mode.
Note that one cycle of discrepancy is introduced between the progress of the program counter and
progress of time once a wait operation occurs.
2-10
LC87BK00 Chapter 2
Table 2.4.1.
Instruction
LD#/LDW#
LD
LDW
ST
STW
MOV
PUSH#
PUSH
PUSHW
PUSH_P
PUSH_BA
POP
Chart of State Transitions of Bit 8 (RAM / SFR) and P1
Bit 8 (RAM/SFR)
P1 (PSW Bit 1)
－
－
－
P1REG8
－
P1REGH8
REG8P1
－
REGL8, REGH8P1
－
REG8P1
－
RAM8P1
－
RAM8REG8
P1REG8
RAMH8REGH8, RAML8REGL8
P1REGH8
RAM8Pl
－
RAMH8P1, RAML8P1
－
REG8RAM8
P1RAM8
POPW
REGH8RAMH8, REGL8RAML8
PlRAMH8
POP_P
POP_BA
XCH
XCHW
INC
－
－
REG8P1
REGH8P1, REGL8Pl, P1REGH8
INC 9 bits
INCW
INC 17 bits, REGL8low byte of CY
DEC
DEC 9 bits
DECW
DBNZ
DEC 17 bits,
REGL8 low byte of CY inverted
DEC 9 bits
P1RAMl (bit l)
P1RAMH8
Same as left.
Same as left.
P1REG8 after
computation
P1REGH8 after
computation
P1REG8 after
computation
P1REGH8 after
computation
P1REG8
DBZ
DEC 9 bits
P1REG8
SET1
NOT1
CLR1
BPC
BP
BN
MUL24/
DIV24
－
－
－
－
－
－
RAM8"1"
－
－
－
－
－
－
－
FUNC
－
－
Remarks
P1bit1 when PSW is
popped
P1bit1 when highorder address of PSW is
popped
Bit 8 ignored
INC 9 bits
INC 17 bits
DEC 9 bits
DEC 17 bits
DEC 9 bits, check loworder 8 bits
DEC 9 bits, check loworder 8 bits
Bit 8 of RAM address
for storing results is set
to 1.
Note: A "1" is read if the processing target is an 8-bit register (no bit 8).
Legends:
REG8:
Bit 8 of a RAM or SFR location
REGH8/REGL8:
Bit 8 of the high-order byte/the low-order byte of a RAM location or SFR
RAM8:
Bit 8 of a RAM location
RAMH8/RAML8: Bit 8 of the high-order byte/the low-order byte of a RAM location
2-11
2-12
LC87BK00 Chapter 3
3. Peripheral System Configuration
This chapter describes the internal functional blocks (peripheral systems) of this series of microcontrollers
except the CPU core, RAM, and ROM. Port block diagrams are provided in Appendix-II for reference.
3.1 Port 0
3.1.1 Overview
Port 0 is an 8-bit I/O port equipped with programmable pull-up resistors. It consists of a data latch, a data
direction register, and a control circuit. The I/O direction and pull-up registers are determined by the data
direction register in 4-bit units.
This port can also be used as a pin for external interrupts and can release HOLD mode. As a user option,
either CMOS output with a programmable pull-up resistor or N-channel open drain output can be selected
as the output type in 1-bit units.
<Notes on the flash ROM version>
Port P05 is temporarily set low when the microcontroller is reset. During the reset sequence, do not
apply a clock or any medium voltage level signal (including Hi-Z) to port P07.
For the treatment of the on-chip debugger pins, refer to the separately available documents entitled "RD87
On-chip Debugger Installation Manual" and Appendix-III "LC872000/LC87B000 Series On-chip
Debugger Pin Processing."
3.1.2 Functions
1)
Input/output port (8 bits: P00 to P07)
• The port output data is controlled by port 0 data latch (P0: FE40) in 1-bit units.
• I/O control of P00 to P03 is accomplished by P0LDDR (P0DDR: FE41, bit 0).
• I/O control of P04 to P07 is accomplished by P0HDDR (P0DDR: FE41, bit 1).
• Ports selected as CMOS output as a user option are provided with programmable pull-up
resistors.
• The programmable pull-up resistors may be of either low impedance or high impedance type
(user selectable).
• The programmable pull-up resistors for P00 to P03 are controlled by P0LPU (P0DDR: FE41,
bit 2). Their type (either low impedance or high impedance) is selected by P0LPUS (P0DDR:
FE41, bit 6).
• The programmable pull-up resistors for P04 to P07 are controlled by P0HPU (P0DDR: FE41,
bit 3). Their type (either low impedance or high impedance) is selected by P0HPUS (P0DDR:
FE41, bit 7).
2)
Interrupt pin function
P0FLG (P0DDR: FE41, bit 5) is set when an input port is specified and 0 level data is input to one of
port bits whose corresponding bit in the port 0 data latch (P0: FE40) is set to 1.
In this case, if P0IE (P0DDR: FE41, bit 4) is 1, HOLD mode is released and an interrupt request to
vector address 004BH is generated.
3-1
Port 0
3)
Multiplexed pin function
P05 also serves as the system clock output, P06 as the timer 6 toggle output, P07 as the timer 7
toggle output, and P00 to P06 as the analog input channel AN0 to AN6.
Address
Initial Value
R/W
Name
BIT7
BIT6
BIT5
BIT4
BIT3
BIT2
FE40
0000 0000
R/W
P0
P07
P06
P05
P04
P03
P02
FE41
0000 0000
R/W
P0DDR
P0HPUS
P0LPUS
P0FLG
P0IE
P0HPU
P0LPU
FE42
00HH 0000
R/W
P0FCR
T7OE
T6OE
-
-
BIT1
BIT0
P01
P00
P0HDDR P0LDDR
CLKOEN CKODV2 CKODV１ CKODV0
3.1.3 Related Registers
3.1.3.1 Port 0 data latch (P0)
1)
2)
3)
This latch is an 8-bit register that controls port 0 output data and port 0 interrupts.
When this register is read with an instruction, data at pins P00 to P07 is read in. If P0 (FE40) is
manipulated using a NOT1, CLR1, SET1, DBZ, DBNZ, INC, or DEC instruction, the contents of the
register are referenced instead of the data at port pins.
Port 0 data can always be read regardless of the I/O state of the port.
Address
Initial Value
R/W
Name
BIT7
BIT6
BIT5
BIT4
BIT3
BIT2
BIT1
BIT0
FE40
0000 0000
R/W
P0
P07
P06
P05
P04
P03
P02
P01
P00
3.1.3.2 Port 0 data direction register (P0DDR)
1)
This register is an 8-bit register that controls the I/O direction of port 0 data in 4-bit units, the pull-up
resistors in 4-bit units, and port 0 interrupts.
Address
Initial Value
R/W
Name
BIT7
BIT6
BIT5
BIT4
BIT3
BIT2
FE41
0000 0000
R/W
P0DDR
P0HPUS
P0LPUS
P0FLG
P0IE
P0HPU
P0LPU
BIT1
BIT0
P0HDDR P0LDDR
P0HPUS (bit 7): P07 to P04 high/low impedance pull-up resistor select
A 1 in this bit selects high impedance pull-up resistors for P07 to P04 and a 0 selects low impedance
pull-up resistors.
P0LPUS (bit 6): P03 to P00 high/low impedance pull-up resistor select
A 1 in this bit selects high impedance pull-up resistors for P03 to P00 and a 0 selects low impedance
pull-up resistors.
P0FLG (bit 5): P0 interrupt source flag
This flag is set when a low level is applied to port 0 set as input and the corresponding P0 (FE40) bit is set.
A HOLD mode release signal and an interrupt request to vector address 004BH are generated when this bit
and the interrupt request enable bit (P0IE) are set to 1.
This bit must be cleared with an instruction as it is not cleared automatically.
P0IE (bit 4): P0 interrupt request enable
Setting this bit and P0FLG to 1 generates a HOLD mode release signal and an interrupt request to vector
address 004BH
P0HPU (bit 3): P07 to P04 pull-up resistor control
When this bit is set to 1 and P0HDDR to 0, pull-up resistors are connected to port bits P07 to P04 that are
selected as CMOS output by option.
3-2
LC87BK00 Chapter 3
P0LPU (bit 2): P03 to P00 pull-up resistor control
When this bit is set to 1 and P0LDDR to 0, pull-up resistors are connected to port bits P03 to P00 that are
selected as CMOS output by option.
P0HDDR (bit 1): P07 to P04 I/O control
When this bit is set to 1, P07 to P04 are placed in output mode and the contents of the corresponding port 0
data latch (P0) are output from the port.
When this bit is set to 0, P07 to P04 are placed in input mode. P0FLG is set when a low level is detected at
a port whose corresponding port 0 data latch (P0) bit is set to 1.
P0LDDR (bit 0): P03 to P00 I/O control
When this bit is set to 1, P03 to P00 are placed in output mode and the contents of the corresponding port 0
data latch (P0) are output from the port.
When this bit is set to 0, P03 to P00 are placed in the input mode. P0FLG is set when a low level is
detected at a port whose corresponding port 0 data latch (P0) bit is set to 1.
P07 to P04 pull-up resistor selection settings
P0HPUS
X
X
0
1
P0HPU
0
0
1
1
Port for Which P0HDDR=0 and CMOS Option is Specified
Pull-up resistor OFF
Pull-up resistor OFF
Low impedance, pull-up resistor ON
High impedance, pull-up resistor ON
P03 to P00 pull-up resistor selection settings
P0LPUS
X
X
0
1
P0LPU
0
0
1
1
Port for Which P0LDDR=0 and CMOS Option is Specified
Pull-up resistor OFF
Pull-up resistor OFF
Low impedance, pull-up resistor ON
High impedance, pull-up resistor ON
3.1.3.3 Port 0 function control register (P0FCR)
1)
This register is a 6-bit register that controls the multiplexed pin outputs of port 0.
Address
Initial Value
R/W
Name
BIT7
BIT6
BIT5
BIT4
FE42
00HH 0000
R/W
P0FCR
T7OE
T6OE
-
-
BIT3
BIT2
CLKOEN CKODV2
BIT1
BIT0
CKODV1
CKODV0
T7OE (bit 7):
This bit controls the output data at pin P07.
This bit is disabled when P07 is in input mode.
When P07 is in output mode:
0: Carries the value of the port data latch.
1: Carries the OR of the waveform that toggles at the interval determined by timer 7 and the value of the
port data latch.
T6OE (bit 6):
This bit controls the output data at pin P06.
This bit is disabled when P06 is in input mode.
When P06 is in output mode:
0: Carries the value of the port data latch.
1: Carries the OR of the waveform that toggles at the interval determined by timer 6 and the value of the
port data latch.
3-3
Port 0
CLKOEN (bit 3):
This bit controls the output data at pin P05.
This bit is disabled when P05 is in input mode.
When P05 is in output mode:
0: Carries the value of the port data latch.
1: Carries the OR of the system clock output and the value of the port data latch.
CKODV2 (bit 2):
CKODV1 (bit 1):
CKODV0 (bit 0):
These bits define the frequency of the system clock to be placed at P05.
000: Frequency of source oscillator selected as system clock
001: 1/2 of frequency of source oscillator selected as system clock
010: 1/4 of frequency of source oscillator selected as system clock
011: 1/8 of frequency of source oscillator selected as system clock
100: 1/16 of frequency of source oscillator selected as system clock
101: 1/32 of frequency of source oscillator selected as system clock
110: 1/64 of frequency of source oscillator selected as system clock
111: Frequency of source oscillator selected as subclock
<Notes on the use of the clock output function>
Follow notes 1) to 3) given below when using the clock output function. Anomalies may be observed in
the waveform of the port clock output if these notes are violated.
1)
Do not change the frequency division setting of the clock output when CLKOEN (bit 3) is set to 1.
 Do not change the settings of CKODV2 to CKODV0 (bits 2 to 0).
2)
Do not change the system clock selection when CLKOEN (bit 3) is set to 1.
 Do not change the settings of CLKCB5 and CLKCB4 (bits 5 and 4) of the OCR register,
SLRCSEL (bit 1) of SLWRC register, and MRCSEL (bit 7) of MRCR register.
3)
CLKOEN will not go to 0 immediately even when the user executes an instruction that loads the
P0FCR register with data that sets the state of CLKOEN (bit 3) from 1 to 0. CLKOEN is set to 0 at
the end of the clock that is being output (on detection of a falling edge of the clock). Accordingly,
when changing the frequency division setting of the clock or changing the system clock selection
after setting CLKOEN to 0 with an instruction, be sure to read the CLKOEN value in advance and
make sure that it is 0.
3.1.4 Options
Two user options are available.
1)
CMOS output (with a programmable pull-up resistor)
2)
N-channel open drain output
3.1.5 HALT and HOLD Mode Operation
When in HALT or HOLD mode, port 0 retains the state that is established when HALT or HOLD mode is
entered.
3-4
LC87BK00 Chapter 3
3.2 Port 1
3.2.1 Overview
Port 1 is an 8-bit I/O port equipped with programmable pull-up resistors. It consists of a data latch, a data
direction register, a function control register, and a control circuit. The I/O direction is determined by the
data direction register in 1-bit units. Port 1 can also be used as a serial interface I/O port or PWM output
port by manipulating the function control register.
As a user option, either CMOS output with a programmable pull-up resistor or N-channel open drain
output with a programmable pull-up resistor can be selected as the output type in 1-bit units.
<Notes on the flash ROM version>
Port P15 is temporarily set low when the microcontroller is reset. During the reset sequence, do not
apply a clock or any medium voltage level signal (including Hi-Z) to port P13.
For the treatment of the on-chip debugger pins, refer to the separately available documents entitled "RD87
On-chip Debugger Installation Manual" and Appendix-III "LC872000/LC87B000 Series On-chip
Debugger Pin Processing."
3.2.2 Functions
1)
Input/output port (8 bits: P10 to P17)
• The port output data is controlled by the port 1 data latch (P1: FE44) and the I/O direction is
controlled by the port 1 data direction register (P1DDR: FE45).
• Each port bit is provided with a programmable pull-up resistor.
2)
Interrupt input pin function
• P17 is assigned to INT1 and is used to detect a low or high level, or a low or high edge and to
set the interrupt flag.
• P16 and P15 are assigned to INT2 and INT3, respectively, and used to detect a low or high
edge, or both edges and to set the interrupt flag.
3)
Timer 0 count input function
A count signal is sent to timer 0 each time a signal change that sets the interrupt flag is supplied to a
port selected from P16 and P15.
4)
Timer 0L capture input function
A timer 0L capture signal is sent each time a signal change that sets the interrupt flag is supplied to a
port selected from P70 and P16.
When a selected level of signal is input to P70 that is specified for level-triggered interrupts, a timer
0L capture signal is generated at 1-cycle intervals for the duration of the input signal.
5)
Timer 0H capture input function
A timer 0H capture signal is sent each time a signal change that sets the interrupt flag is supplied to a
port selected from P17 and P15.
When a selected level of signal is input to P17 that is specified for level-triggered interrupts, a timer
0H capture signal is generated at 1-cycle intervals for the duration of the input signal.
3-5
Port 1
6)
HOLD mode release function
• When the interrupt flag and interrupt enable flag are set by INT1 or INT2, a HOLD mode
release signal is generated, releasing HOLD mode. The CPU then enters HALT mode (main
oscillation by medium-speed RC or low-speed RC oscillator). When the interrupt is accepted,
the CPU switches from HALT mode to normal operating mode.
• When the signal level that sets an interrupt flag is input to P17 that is specified for
level-triggered interrupts in HOLD mode, the interrupt flag is set. In this case, if the
corresponding interrupt enable flag is set, HOLD mode is released.
• When a signal change that sets an interrupt flag is input to P16 in HOLD mode, the interrupt
flag is set. In this case, HOLD mode is released if the corresponding interrupt enable flag is set.
The interrupt flag, however, cannot be set by a rising edge occurring when the P16 data that is
established when HOLD mode is entered is in the high state, or by a falling edge occurring
when P16 data that is established when HOLD mode is entered is in the low state.
Consequently, to release HOLD mode with P16, it is recommended that P16 be used in
both-edge interrupt mode.
7)
Multiplexed pin functions
• P17 also serves as the timer 1 PWMH or base timer BUZ output, P16 as the timer 1 PWML
output, and P15 to P13 as SIO1 I/O.
P17
P16
P15
Input
Output
With a
programmable
pull-up
resistor
CMOS/N-channel
open drain
Interrupt Input
Timer 0
Capture HOLD Mode
Signal Detection Count Input
Input
Release
L level, H level,

Timer 0H
Enabled
(Note)
L edge, H edge
L edge, H edge,
Yes
Timer 0L
Enabled
Both edges
Yes
Timer 0H

Note: P17 HOLD mode release is enabled only when level detection is set.
Address
Initial Value
R/W
Name
BIT7
BIT6
BIT5
BIT4
BIT3
BIT2
BIT1
BIT0
FE44
0000 0000
R/W
P1
P17
P16
P15
P14
P13
P12
P11
P10
FE45
0000 0000
R/W
P1DDR
P17DDR P16DDR P15DDR P14DDR P13DDR P12DDR P11DDR P10DDR
FE46
0000 0000
R/W
P1FCR
P17FCR
P16FCR
P15FCR
P14FCR
P13FCR
P12FCR
P11FCR
FE47
0000 HHH0
R/W
P1TST
FIX0
FIX0
FIX0
FIX0
-
-
-
FIX0
FE5D
0000 0000
R/W
I01CR
INT1LH
INT1LV
INT1IF
INT1IE
INT0LH
INT0LV
INT0IF
INT0IE
FE5E
0000 0000
R/W
I23CR
INT3IF
INT3IE INT2HEG INT2LEG
INT2IF
INT2IE
FE5F
0000 0000
R/W
ISL
NFON
ST0IN
INT3HEG INT3LEG
ST0HCP
ST0LCP
BTIMC1 BTIMC0
BUZON
NFSEL
P10FCR
Bits 7 to 4 and 0 of P1TST (FE47) are reserved for testing. They must always be set to 0.
3.2.3 Related Registers
3.2.3.1 Port 1 data latch (P1)
1)
2)
3)
This latch is an 8-bit register that controls port 1 output data and pull-up resistors.
When this register is read with an instruction, data at pins P10 to P17 is read in. If P1 (FE44) is
manipulated using a NOT1, CLR1, SET1, DBZ, DBNZ, INC, or DEC instruction, the contents of the
register are referenced instead of the data at port pins.
Port 1 data can always be read regardless of the I/O state of the port.
Address
Initial Value
R/W
Name
BIT7
BIT6
BIT5
BIT4
BIT3
BIT2
BIT1
BIT0
FE44
0000 0000
R/W
P1
P17
P16
P15
P14
P13
P12
P11
P10
3-6
LC87BK00 Chapter 3
3.2.3.2 Port 1 data direction register (P1DDR)
1)
2)
This register is an 8-bit register that controls the I/O direction of port 1 data in 1-bit units. Port P1n is
placed in output mode when bit P1nDDR is set to 1 and in input mode when bit P1nDDR is set to 0.
When bit P1nDDR is set to 0, and bit P1n of the port 1 data latch is set to 1, port P1n becomes an
input with a pull-up resistor.
Address
Initial Value
R/W
Name
FE45
0000 0000
R/W
P1DDR
Register Data
P1n
P1nDDR
0
0
1
0
0
1
1
1
Input
Enabled
Enabled
Enabled
Enabled
BIT7
BIT6
BIT5
BIT4
BIT3
BIT2
BIT1
BIT0
P17DDR P16DDR P15DDR P14DDR P13DDR P12DDR P11DDR P10DDR
Port P1n State
Output
Internal Pull-up
Resistor
OFF
ON
OFF
OFF
Open
Internal pull-up resistor
Low
High/open (CMOS/N-channel open drain)
3.2.3.3 Port 1 function control register (P1FCR)
1)
This register is an 8-bit register that controls the multiplexed pin outputs of port 1.
Address
Initial Value
R/W
Name
BIT7
BIT6
BIT5
BIT4
BIT3
BIT2
BIT1
BIT0
FE46
0000 0000
R/W
P1FCR
P17FCR
P16FCR
P15FCR
P14FCR
P13FCR
P12FCR
P11FCR
P10FCR
n
7
P1nFCR
P1n
P1n Pin Data in Output Mode (P1nDDR=1)
0
–
Value of port data latch (P17)
1
0
Timer 1 PWMH or base timer BUZ data
1
1
Timer 1 PWMH or base timer BUZ inverted data
6
0
–
Value of port data latch (P16)
1
0
Timer 1 PWML data
1
1
Timer 1 PWML inverted data
5
0
–
Value of port data latch (P15)
1
0
SIO1 clock output data
1
1
High output
4
0
–
Value of port data latch (P14)
1
0
SIO1 output data
1
1
High output
3
0
–
Value of port data latch (P13)
1
0
SIO1 output data
1
1
High output
2
0
–
Value of port data latch (P12)
1
0
Low output
1
1
High output
1
0
–
Value of port data latch (P11)
1
0
Low output
1
1
High output
0
0
–
Value of port data latch (P10)
1
0
Low output
1
1
High output
The high data output at a pin that is selected as an N-channel open drain output (by user option) is represented
by an open circuit.
3-7
Port 1
P17FCR (bit 7): P17 function control (timer 1 PWMH or base timer BUZ output control)
This bit controls the output data at pin P17.
When P17 is placed in output mode (P17DDR = 1) and P17FCR is set to 1, timer 1 PWMH output or BUZ
output from the base timer is EORed with the port data latch and the result is placed at pin P17.
* Selection between timer 1 PWMH and the base timer BUZ output is accomplished by BUZON (ISL: FE5F,
bit 3).
P16FCR (bit 6): P16 function control (timer 1 PWML output control)
This bit controls the output data at pin P16.
When P16 is placed in output mode (P16DDR = 1) and P16FCR is set to 1, the EOR of timer 1 PWML
output data and the port data latch is placed at pin P16.
P15FCR (bit 5): P15 function control (SIO1 clock output control)
This bit controls the output data at pin P15.
When P15 is placed in output mode (P15DDR = 1) and P15FCR is set to 1, the OR of the SIO1 clock
output data and the port data latch is placed at pin P15.
P14FCR (bit 4): P14 function control (SIO1 data output control)
This bit controls the output data at pin P14.
When P14 is placed in output mode (P14DDR = 1) and P14FCR is set to 1, the OR of the SIO1 output data
and the port data latch is placed at pin P14.
When the SIO1 is active, SIO1 input data is read in from P14 regardless of the I/O state of P14.
P13FCR (bit 3): P13 function control (SIO1 data output control)
This bit controls the output data at pin P13.
When P13 is placed in output mode (P13DDR = 1) and P13FCR is set to 1, the OR of the SIO1 output data
and the port data latch is placed at pin P13.
P12FCR (bit 2): P12 function control
This bit controls the output data at pin P12.
When P12 is placed in output mode (P12DDR = 1) and P12FCR is set to 1, the value of the port data latch
is placed at pin P12.
P11FCR (bit 1): P11 function control
This bit controls the output data at pin P11.
When P11 is placed in output mode (P11DDR = 1) and P11FCR is set to 1, the value of the port data latch
is placed at pin P11.
P10FCR (bit 0): P10 function control
This bit controls the output data at pin P10.
When P10 is placed in output mode (P10DDR = 1) and P10FCR is set to 1, the value of the port data latch
is placed at pin P10.
3-8
LC87BK00 Chapter 3
3.2.3.4 External interrupt 0/1 control register (I01CR)
1)
This register is an 8-bit register that controls external interrupts 0 and 1.
Address
Initial Value
R/W
Name
BIT7
BIT6
BIT5
BIT4
BIT3
BIT2
BIT1
BIT0
FE5D
0000 0000
R/W
I01CR
INT1LH
INT1LV
INT1IF
INT1IE
INT0LH
INT0LV
INT0IF
INT0IE
INT1LH (bit 7): INT1 detection polarity select
INT1LV (bit 6): INT1 detection level/edge select
INT1LH
0
0
1
1
INT1LV
0
1
0
1
INT1 Interrupt Conditions (P17 Pin Data)
Falling edge detected
Low level detected
Rising edge detected
High level detected
INT1IF (bit 5): INT1 interrupt source flag
This bit is set when the conditions specified by INT1LH and INT1LV are satisfied. When this bit and the
INT1 interrupt request enable bit (INT1IE) are set to 1, a HOLD mode release signal and an interrupt
request to vector address 000BH are generated.
This bit must be cleared with an instruction as it is not cleared automatically.
INT1IE (bit 4): INT1 interrupt request enable
When this bit and INT1IF are set to 1, a HOLD mode release signal and an interrupt request to vector
address 000BH are generated.
INT0LH (bit 3): INT0 detection polarity select
INT0LV (bit 2): INT0 detection level/edge select
INT0LH
0
0
1
1
INT0LV
0
1
0
1
INT0 Interrupt Conditions (P70 Pin Data)
Falling edge detected
Low level detected
Rising edge detected
High level detected
INT0IF (bit 1): INT0 interrupt source flag
This bit is set when the conditions specified by INT0LH and INT0LV are satisfied. When this bit and the
INT0 interrupt request enable bit (INT0IE) are set to 1, a HOLD mode release signal and an interrupt
request to vector address 0003H are generated.
This bit must be cleared with an instruction as it is not cleared automatically.
INT0IE (bit 0): INT0 interrupt request enable
When this bit and INT0IF are set to 1, a HOLD mode release signal and an interrupt request to vector
address 0003H are generated.
Note: INT0 HOLD mode release function is available only when level detection is set.
3.2.3.5 External interrupt 2/3 control register (I23CR)
1)
This register is an 8 bit register that controls external interrupts 2 and 3.
Address
Initial Value
FE5E
0000 0000
R/W Name
BIT7
BIT6
R/W I23CR INT3HEG INT3LEG
BIT5
BIT4
INT3IF
INT3IE
3-9
BIT3
BIT2
INT2HEG INT2LEG
BIT1
BIT0
INT2IF
INT2IE
Port 1
INT3HEG (bit 7): INT3 rising edge detection control
INT3LEG (bit 6): INT3 falling edge detection control
INT3HEG
0
0
1
1
INT3LEG
0
1
0
1
INT3 Interrupt Conditions (P15 Pin Data)
No edge detected
Falling edge detected
Rising edge detected
Both edges detected
INT3IF (bit 5): INT3 interrupt source flag
This bit is set when the conditions specified by INT3HEG and INT3LEG are satisfied. When this bit and
the INT3 interrupt request enable bit (INT3IE) are set to 1, an interrupt request to vector address 001BH is
generated.
This bit must be cleared with an instruction as it is not cleared automatically.
INT3IE (bit 4): INT3 interrupt request enable
When this bit and INT3IF are set to 1, an interrupt request to vector address 001BH is generated.
INT2HEG (bit 3): INT2 rising edge detection control
INT2LEG (bit 2): INT2 falling edge detection control
INT2HEG
0
0
1
1
INT2LEG
0
1
0
1
INT2 Interrupt Conditions (P16 Pin Data)
No edge detected
Falling edge detected
Rising edge detected
Both edges detected
INT2IF (bit 1): INT2 interrupt source flag
This bit is set when the conditions specified by INT2HEG and INT2LEG are satisfied.
When this bit and the INT2 interrupt request enable bit (INT2IE) are set to 1, a HOLD mode release signal
and an interrupt request to vector address 0013H are generated.
The interrupt flag, however, cannot be set by a rising edge occurring when P16 data that is established
when HOLD mode is entered is in the high state, or by a falling edge occurring when P16 data that is
established when HOLD mode is entered is in the low state. Consequently, to release HOLD mode with
P16, it is recommended that P16 be used in both-edge interrupt mode.
This bit must be cleared with an instruction as it is not cleared automatically.
INT2IE (bit 0): INT2 interrupt request enable
When this bit and INT2IF are set to 1, a HOLD mode release signal and an interrupt request to vector
address 0013H are generated.
3.2.3.6 Input signal select register (ISL)
1)
This register is an 8-bit register that controls the timer 0 input, noise filter time constant, buzzer
output/timer 1 PWMH output select, and base timer clock select.
Address
Initial Value
R/W
Name
BIT7
BIT6
FE5F
0000 0000
R/W
ISL
ST0HCP
ST0LCP
BIT5
BIT4
BTIMC1 BTIMC0
3-10
BIT3
BIT2
BIT1
BIT0
BUZON
NFSEL
NFON
ST0IN
LC87BK00 Chapter 3
ST0HCP (bit 7): Timer 0H capture signal input port select
This bit selects the timer 0H capture signal input port.
When this bit is set to 1, a timer 0H capture signal is generated when an input that satisfies the INT1
interrupt detection conditions is supplied to P17. If the INT1 interrupt detection mode is set to level
detection, capture signals are generated at an interval of 1 Tcyc as long as the detection level is present at
P17.
When this bit is set to 0, a timer 0H capture signal is generated when an input that satisfies the INT3
interrupt detection conditions is supplied to P15.
ST0LCP (bit 6): Timer 0L capture signal input port select
This bit selects the timer 0L capture signal input port.
When this bit is set to 1, a timer 0L capture signal is generated when an input that satisfies the INT0
interrupt detection conditions is supplied to P70. If the INT0 interrupt detection mode is set to level
detection, capture signals are generated at an interval of 1 Tcyc as long as the detection level is present at
P70.
When this bit is set to 0, a timer 0L capture signal is generated when an input that satisfies the INT2
interrupt detection conditions is supplied to P16.
BTIMC1 (bit 5): Base timer clock select
BTIMC0 (bit 4): Base timer clock select
BTIMC1
0
0
1
1
BTIMC0
0
1
0
1
Base Timer Input Clock
Subclock
Cycle clock
Subclock
Timer/counter 0 prescaler output
BUZON (bit 3): Buzzer output/timer 1 PWMH output select
When P17FCR (P1FCR, bit 7) is set to 1, this bit selects the data (buzzer output or timer 1 PWMH output)
to be sent to P17.
When this bit is set to 1, the timer 1 PWMH output is fixed high and a signal derived by dividing the base
timer clock by 16 (fBST/16) is sent to P17 as buzzer output.
When this bit is set to 0, the buzzer output is fixed high, and the timer 1 PWMH output data is sent to
P17.
fBST: The frequency of the input clock to the base timer that is selected through the input signal
select register (ISL), bits 5 and 4..
NFSEL (bit 2): Noise filter time constant select
NFON (bit 1): Noise filter time constant select
NFSEL
0
0
1
1
NFON
0
1
0
1
Noise Filter Time Constant
1 Tcyc
128 Tcyc
1 Tcyc
32 Tcyc
ST0IN (bit 0): Timer 0 count clock input port select
This bit selects the timer 0 count clock signal input port.
When this bit is set to 1, a timer 0 count clock is generated when an input that satisfies the INT3 interrupt
detection conditions is supplied to P15.
When this bit is set to 0, a timer 0 count clock is generated when an input that satisfies the INT2 interrupt
detection conditions is supplied to P16.
Note: When timer 0L capture signal input or timer 0H capture signal input is specified for INT4 together
with P70 or P17 to P15, the signal from P70 or P17 to P15 is ignored.
3-11
Port 1
3.2.4 Options
Two user options are available.
1)
CMOS output
2)
N-channel open drain output
(with a programmable pull-up resistor)
(with a programmable pull-up resistor)
3.2.5 HALT and HOLD Mode Operation
When in HALT or HOLD mode, port 1 retains the state that is established when HALT or HOLD mode is
entered.
3-12
LC87BK00 Chapter 3
3.3 Port 2
3.3.1 Overview
Port 2 is a 2-bit I/O port equipped with programmable pull-up resistors. It consists of a data latch, a data
direction register, and a control circuit. The I/O direction is determined by the data direction register in
1-bit units.
Port 2 can also serve as an input port for external interrupts. It can also be used as a port for the timer 1
count clock input, timer 0 capture signal input, and HOLD mode release signal input.
As a user option, either CMOS output with a programmable pull-up resistor or N-channel open drain
output with a programmable pull-up resistor can be selected as the output type in 1-bit units.
3.3.2 Functions
1)
Input/output port (2 bits: P20 and P21)
• The port output data is controlled by the port 2 data latch (P2: FE48) and the I/O direction is
controlled by the port 2 data direction register (P2DDR: FE49).
• Each port bit is provided with a programmable pull-up resistor.
2)
Interrupt input pin function
The port (INT4) selected from P20 and P21 is provided with a pin interrupt function, respectively.
This function detects a low edge, a high edge, or both edges and sets the interrupt flag. These two
selected ports can also be used as timer 1 count clock input or timer 0 capture signal input.
3)
HOLD mode release function
• When the interrupt flag and interrupt enable flag are set by INT4, a HOLD mode release signal
is generated, releasing HOLD mode. The CPU then enters HALT mode (medium- or low-speed
RC oscillator selected as system clock). When the interrupt is accepted, the CPU switches from
HALT mode to normal operating mode.
• When a signal change that sets the INT4 interrupt flag is input in HOLD mode, an interrupt
flag is set. In this case, HOLD mode is released if the corresponding interrupt enable flag is set.
The interrupt flag, however, cannot be set by a rising edge occurring when INT4 data that is
established when HOLD mode is entered is in the high state, or by a falling edge occurring
when INT4 data that is established when HOLD mode is entered is in the low state.
Consequently, to release HOLD mode with INT4, it is recommended that INT4 be used in
both-edge interrupt mode.
Address Initial Value
R/W
Name
BIT7
BIT6
BIT5
BIT4
BIT3
BIT2
BIT1
FE48
HHHH HH00
R/W
P2
-
-
-
-
-
-
P21
P20
FE49
HHHH HH00
R/W
P2DDR
-
-
-
-
-
-
P21DDR
P20DDR
FE4A
0000 0000
R/W
I45CR
FIX0
FIX0
FIX0
FIX0
INT4IF
INT4IE
FE4B
0000 0000
R/W
I45SL
FIX0
FIX0
FIX0
FIX0
I4SL1
I4SL0
3-13
INT4HEG INT4LEG
I4SL3
I4SL2
BIT0
Port 2
3.3.3 Related Registers
3.3.3.1 Port 2 data latch (P2)
1)
2)
3)
This latch is a 2-bit register that controls port 2 output data and pull-up resistors.
When this register is read with an instruction, data at pins P20 and P21 is read in. If P2 (FE48) is
manipulated using a NOT1, CLR1, SET1, DBZ, DBNZ, INC, or DEC instruction, the contents of the
register are referenced instead of the data at port pins.
Port 2 data can always be read regardless of the I/O state of the port.
Address
Initial Value
R/W
Name
BIT7
BIT6
BIT5
BIT4
BIT3
BIT2
BIT1
BIT0
FE48
HHHH HH00
R/W
P2
-
-
-
-
-
-
P21
P20
3.3.3.2 Port 2 data direction register (P2DDR)
1)
2)
This register is a 2-bit register that controls the I/O direction of port 2 data in 1-bit units. Port P2n is
placed in output mode when bit P2nDDR is set to 1 and in input mode when bit P2nDDR is set to 0.
When bit P2nDDR is set to 0 and bit P2n of the port 2 data latch is set to 1, port P2n becomes an
input with a pull-up resistor
Address
Initial Value
R/W
Name
BIT7
BIT6
BIT5
BIT4
BIT3
BIT2
FE49
HHHH HH00
R/W
P2DDR
-
-
-
-
-
-
Register Data
P2n
P2nDDR
0
0
1
0
0
1
1
1
Input
Enabled
Enabled
Enabled
Enabled
Port P2n State
Output
BIT1
BIT0
P21DDR P20DDR
Internal Pull-up
Resistor
OFF
ON
OFF
OFF
Open
Internal pull-up resistor
Low
High/open (CMOS/N-channel open drain)
3.3.3.3 External interrupt 4/5 control register (I45CR)
1)
This register is an 8-bit register that controls external interrupts 4 and 5.
Address Initial Value R/W
FE4A
0000 0000
R/W
Name
BIT7
BIT6
BIT5
BIT4
I45CR
FIX0
FIX0
FIX0
FIX0
BIT3
BIT2
INT4HEG INT4LEG
BIT1
BIT0
INT4IF
INT4IE
FIX0 (bits 7 to 4): Fixed bits
These bits must always be set to 0.
INT4HEG (bit 3): INT4 rising edge detection control
INT4LEG (bit 2): INT4 falling edge detection control
INT4HEG
0
0
1
1
INT4LEG
0
1
0
1
INT4 Interrupt Conditions (Pin Data)
No edge detected
Falling edge detected
Rising edge detected
Both edges detected
INT4IF (bit 1): INT4 interrupt source flag
This bit is set when the conditions specified by INT4HEG and INT4LEG are satisfied.
When this bit and the INT4 interrupt request enable bit (INT4IE) are set to 1, a HOLD mode release signal
and an interrupt request to vector address 0013H are generated.
3-14
LC87BK00 Chapter 3
The interrupt flag, however, cannot be set by a rising edge occurring when the INT4 data that is
established when HOLD mode is entered is in the high state, or by a falling edge occurring when the INT4
data that is established when HOLD mode is entered is in the low state. Consequently, to release HOLD
mode with INT4, it is recommended that INT4 be used in both-edge interrupt mode.
This bit must be cleared with an instruction as it is not cleared automatically.
INT4IE (bit 0): INT4 interrupt request enable
When this bit and INT4IF are set to 1, a HOLD mode release signal and an interrupt request to vector
address 0013H are generated.
3.3.3.4 External interrupt 4/5 pin select register (I45SL)
1)
This register is an 8-bit register used to select pins for the external interrupts 4 and 5.
Address
Initial Value
R/W
Name
BIT7
BIT6
BIT5
BIT4
BIT3
BIT2
BIT1
BIT0
FE4B
0000 0000
R/W
I45SL
FIX0
FIX0
FIX0
FIX0
I4SL3
I4SL2
I4SL1
I4SL0
FIX0 (bits 7 to 4): Fixed bits
These bits must always be set to 0.
I4SL3 (bit 3): INT4 pin select
I4SL2 (bit 2): INT4 pin select
I4SL3
0
0
1
1
I4SL2
0
1
0
1
Pin Assigned to INT4
P20
P21
Inhibited
Inhibited
I4SL1 (bit 1): INT4 pin function select
I4SL0 (bit 0): INT4 pin function select
When the data change specified in the external interrupt 4/5 control register (I45CR) is given to the pin
that is assigned to INT4, timer 1 count clock input and timer 0 capture signal are generated.
I4SL1
0
0
1
1
I4SL0
0
1
0
1
Function other than INT4 Interrupt
None
Timer 1 count clock input
Timer 0L capture signal input
Timer 0H capture signal input
Notes:
1) When timer 0L capture signal input or timer 0H capture signal input is specified for INT4 together with
P70 or P17 to P15, the signal from P70 or P17 to P15 is ignored.
2) When INT4 is specified as timer 1 count clock input, timer 1L functions as an event counter. If INT4 is not
specified for timer 1 count clock input, the timer 1L counter counts on every 2Tcyc.
3-15
Port 2
3.3.4 Options
Two user options are available.
1)
CMOS output
2)
N-channel open drain output
(with a programmable pull-up resistor)
(with a programmable pull-up resistor)
3.3.5 HALT and Hold Mode Operation
When in HALT or HOLD mode, port 2 retains the state that is established when HALT or HOLD mode is
entered.
3-16
LC87BK00 Chapter 3
3.4 Port 7
3.4.1 Overview
Port 7 is a 1-bit I/O port equipped with programmable pull-up resistors. It consists of a data control latch
and a control circuit. The I/O direction is determined in 1-bit units.
Port 7 can be used as an input port for external interrupts. It can also be used as a port for the capture
signal input or HOLD mode release signal input.
There is no user option for this port.
3.4.2 Functions
1)
Input/output port (1 bit: P70)
• The port output data is controlled by bit 0 of the port 7 control register (P7: FE5C) and the I/O
direction is controlled by bit 4.
• P70 is N-channel open drain output type.
• The port bit is provided with a programmable pull-up resistor.
2)
Interrupt input pin function
• P70 is assigned to INT0, and is used to detect a low or high level, or a low or high edge and to
set the interrupt flag.
3)
Timer 0L capture input function
A timer 0L capture signal is generated each time a signal change that sets the interrupt flag is
supplied to the port selected from P70 and P16.
When a selected level of signal is input to P70 that is specified for level-triggered interrupts, a timer
0L capture signal is generated at 1-cycle intervals for the duration of the input signal.
4)
HOLD mode release function
• When the interrupt flag and interrupt enable flag are set by INT0, a HOLD mode release signal
is generated, releasing HOLD mode. The CPU then enters HALT mode (medium- or low-speed
RC oscillator selected as system clock). When the interrupt is accepted, the CPU switches from
HALT mode to normal operating mode.
• When a signal change that sets the interrupt flag is input to P70 that is specified for
level-triggered interrupts in HOLD mode, the interrupt flag is set. In this case, HOLD mode is
released if the corresponding interrupt enable flag is set.
5)
Multiplexed pin function
• P70 also serves as the AN8 analog input channel function.
3-17
Port 7
Input
Interrupt Input
Signal Detection
L level, H level,
L edge, H edge
Output
Timer 0
Capture HOLD Mode
Count Input Input
Release

Timer 0L Enabled (Note)
N-channel
With
open drain
programmable
pull-up
resistor
Note: P70 HOLD mode release is enabled only when the level detection is set..
P70
Address
Initial Value
FE5C
HHH0 HHH0
R/W Name
FE5D
0000 0000
R/W I01CR
FE5E
0000 0000
R/W I23CR INT3HEG INT3LEG
FE5F
0000 0000
R/W
R/W
BIT7
BIT6
BIT5
BIT4
BIT3
BIT2
BIT1
BIT0
-
-
-
P70DDR
-
-
-
P70DT
INT1LH
INT1LV
INT0LH
INT0LV
INT0IF
INT0IE
INT2IF
INT2IE
NFON
ST0IN
P7
ISL
ST0HCP
ST0LCP
INT1IF
INT1IE
INT3IF
INT3IE
BTIMC1
BTIMC0
INT2HEG INT2LEG
BUZON
NFSEL
3.4.3 Related Registers
3.4.3.1 Port 7 control register (P7)
1)
2)
3)
This register is a 2-bit register that controls the I/O direction of port 7 data and pull-up resistors.
When this register is read with an instruction, data at pin P70 is read into bit 0. Bit 4 is loaded with
bit 4 of register P7. If P7 (FE5C) is manipulated using a NOT1, CLR1, SET1, DBZ, DBNZ, INC, or
DEC instruction, the contents of the register are referenced as bit 0 instead of the data at the port pin.
Port 7 data can always be read regardless of the I/O state of the port
Address
Initial Value
R/W
Name
BIT7
BIT6
BIT5
BIT4
BIT3
BIT2
BIT1
BIT0
FE5C
HHH0 HHH0
R/W
P7
-
-
-
P70DDR
-
-
-
P70DT
Register Data
P70DT
P70DDR
0
0
1
0
0
1
1
1
Input
Enabled
Enabled
Enabled
Enabled
P70 State
Output
Internal Pull-up Resistor
Open
Internal pull-up resistor
N-channel open drain, low
Open
OFF
ON
OFF
ON
(Bits 7 to 5): These bits do not exist.
They are always read as 1.
P70DDR (bit 4): P70 I/O control
A 1 or 0 in this bit controls the output (N-channel open drain) or input of pin P70.
(Bits 3 to 1): These bits do not exist.
They are always read as 1.
P70DT (bit 0): P70 data
The value of this bit is output from pin P70 when P70DDR is set to 1. Since this bit is N-channel open
drain output type, it is placed in the high-impedance state when P70DT is set to 1.
A 1 or 0 in this bit turns on or off the internal pull-up resistor for pin P70.
3-18
LC87BK00 Chapter 3
3.4.3.2 External interrupt 0/1 control register (I01CR)
1)
This register is an 8-bit register that controls external interrupts 0 and 1.
Address
Initial Value
R/W
Name
BIT7
BIT6
BIT5
BIT4
BIT3
BIT2
BIT1
BIT0
FE5D
0000 0000
R/W
I01CR
INT1LH
INT1LV
INT1IF
INT1IE
INT0LH
INT0LV
INT0IF
INT0IE
INT1LH (bit 7): INT1 detection polarity select
INT1LV (bit 6): INT1 detection level/edge select
INT1LH
0
0
1
1
INT1LV
0
1
0
1
INT1 Interrupt Conditions (P17 Pin Data)
Falling edge detected
Low level detected
Rising edge detected
High level detected
INT1IF (bit 5): INT1 interrupt source flag
This bit is set when the conditions specified by INT1LH and INT1LV are satisfied. When this bit and the
INT1 interrupt request enable bit (INT1IE) are set to 1, a HOLD mode release signal and an interrupt
request to vector address 000BH are generated.
This bit must be cleared with an instruction as it is not cleared automatically.
INT1IE (bit 4): INT1 interrupt request enable
When this bit and INT1IF are set to 1, a HOLD mode release signal and an interrupt request to vector
address 000BH are generated.
INT0LH (bit 3): INT0 detection polarity select
INT0LV (bit 2): INT0 detection level/edge select
INT0LH
0
0
1
1
INT0LV
0
1
0
1
INT0 Interrupt Conditions (P70 Pin Data)
Falling edge detected
Low level detected
Rising edge detected
High level detected
INT0IF (bit 1): INT0 interrupt source flag
This bit is set when the conditions specified by INT0LH and INT0LV are satisfied. When this bit and the
INT0 interrupt request enable bit (INT0IE) are set to 1, a HOLD mode release signal and an interrupt
request to vector address 0003H are generated.
This bit must be cleared with an instruction as it is not cleared automatically.
INT0IE (bit 0): INT0 interrupt request enable
When this bit and INT0IF are set to 1, a HOLD mode release signal and an interrupt request to vector
address 0003H are generated.
Note: INT0 HOLD mode release is enabled only when level detection is set.
3.4.3.3 External interrupt 2/3 control register (I23CR)
1)
This register is an 8 bit register that controls external interrupts 2 and 3.
Address
Initial Value
FE5E
0000 0000
R/W Name
BIT7
BIT6
R/W I23CR INT3HEG INT3LEG
BIT5
BIT4
INT3IF
INT3IE
3-19
BIT3
BIT2
INT2HEG INT2LEG
BIT1
BIT0
INT2IF
INT2IE
Port 7
INT3HEG (bit 7): INT3 rising edge detection control
INT3LEG (bit 6): INT3 falling edge detection control
INT3HEG
0
0
1
1
INT3LEG
0
1
0
1
INT3 Interrupt Conditions (P15 Pin Data)
No edge detected
Falling edge detected
Rising edge detected
Both edges detected
INT3IF (bit 5): INT3 interrupt source flag
This bit is set when the conditions specified by INT3HEG and INT3LEG are satisfied. When this bit and
the INT3 interrupt request enable bit (INT3IE) are set to 1, an interrupt request to vector address 001BH is
generated.
This bit must be cleared with an instruction as it is not cleared automatically.
INT3IE (bit 4): INT3 interrupt request enable
When this bit and INT3IF are set to 1, an interrupt request to vector address 001BH is generated.
INT2HEG (bit 3): INT2 rising edge detection control
INT2LEG (bit 2): INT2 falling edge detection control
INT2HEG
0
0
1
1
INT2LEG
0
1
0
1
INT2 Interrupt Conditions (P16 Pin Data)
No edge detected
Falling edge detected
Rising edge detected
Both edges detected
INT2IF (bit 1): INT2 interrupt source flag
This bit is set when the conditions specified by INT2HEG and INT2LEG are satisfied.
When this bit and the INT2 interrupt request enable bit (INT2IE) are set to 1, a HOLD mode release signal
and an interrupt request to vector address 0013H are generated.
The interrupt flag, however, cannot be set by a rising edge occurring when P16 data that is established
when HOLD mode is entered is in the high state, or by a falling edge occurring when P16 data that is
established when HOLD mode is entered is in the low state. Consequently, to release HOLD mode with
P16, it is recommended that P16 be used in both-edge interrupt mode.
This bit must be cleared with an instruction as it is not cleared automatically.
INT2IE (bit 0): INT2 interrupt request enable
When this bit and INT2IF are set to 1, a HOLD mode release signal and an interrupt request to vector
address 0013H are generated.
3.4.3.4 Input signal select register (ISL)
1)
This register is an 8-bit register that controls the timer 0 input, noise filter time constant, buzzer
output/timer 1 PWMH output select, and base timer clock select.
Address
Initial Value
R/W
Name
BIT7
BIT6
FE5F
0000 0000
R/W
ISL
ST0HCP
ST0LCP
BIT5
BIT4
BTIMC1 BTIMC0
3-20
BIT3
BIT2
BIT1
BIT0
BUZON
NFSEL
NFON
ST0IN
LC87BK00 Chapter 3
ST0HCP (bit 7): Timer 0H capture signal input port select
This bit selects the timer 0H capture signal input port.
When this bit is set to 1, a timer 0H capture signal is generated when an input that satisfies the INT1
interrupt detection conditions is supplied to P17. If the INT1 interrupt detection mode is set to level
detection, capture signals are generated at an interval of 1 Tcyc as long as the detection level is present at
P17.
When this bit is set to 0, a timer 0H capture signal is generated when an input that satisfies the INT3
interrupt detection conditions is supplied to P15.
ST0LCP (bit 6): Timer 0L capture signal input port select
This bit selects the timer 0L capture signal input port.
When this bit is set to 1, a timer 0L capture signal is generated when an input that satisfies the INT0
interrupt detection conditions is supplied to P70. If the INT0 interrupt detection mode is set to level
detection, capture signals are generated at an interval of 1 Tcyc as long as the detection level is present at
P70.
When this bit is set to 0, a timer 0L capture signal is generated when an input that satisfies the INT2
interrupt detection conditions is supplied to P16.
BTIMC1 (bit 5): Base timer clock select
BTIMC0 (bit 4): Base timer clock select
BTIMC1
0
0
1
1
BTIMC0
0
1
0
1
Base Timer Input Clock
Subclock
Cycle clock
Subclock
Timer/counter 0 prescaler output
BUZON (bit 3): Buzzer output/timer 1 PWMH output select
When P17FCR (P1FCR, bit 7) is set to 1, this bit selects the data (buzzer output or timer 1 PWMH output)
to be sent to P17.
When this bit is set to 1, the timer 1 PWMH output is fixed high, and a signal that is obtained by dividing
the base timer clock by 16 (fBST/16) is sent to P17 as buzzer output.
When this bit is set to 0, the buzzer output is fixed high, and the timer 1 PWMH output data is sent to P17.
fBST: The frequency of the input clock to the base timer that is selected through the input
signal select register (ISL), bits 5 and 4.
NFSEL (bit 2): Noise filter time constant select
NFON (bit 1): Noise filter time constant select
NFSEL
0
0
1
1
NFON
0
1
0
1
Noise Filter Time Constant
1 Tcyc
128 Tcyc
1 Tcyc
32 Tcyc
3-21
Port 7
ST0IN (bit 0): Timer 0 count clock input port select
This bit selects the timer 0 count clock signal input port.
When this bit is set to 1, a timer 0 count clock is generated when an input that satisfies the INT3 interrupt
detection conditions is supplied to P15.
When this bit is set to 0, a timer 0 count clock is generated when an input that satisfies the INT2 interrupt
detection conditions is supplied to P16.
Note: When timer 0L capture signal input or timer 0H capture signal input is specified for INT4 together with
P70 or P17 to P15, the signal from P70 or P17 to P15 is ignored.
3.4.4 Options
There is no user option for this port.
3.4.5 HALT and HOLD Mode Operation
The pull-up resistor of P70 is turned off.
3-22
LC87BK00 Chapter 3
3.5 Timer/Counter 0 (T0)
3.5.1 Overview
The timer/counter 0 (T0) incorporated in this series of microcontrollers is a 16-bit timer/counter that has
the following four functions:
1)
2)
3)
4)
Mode 0: 8-bit programmable timer with a programmable prescaler (with an 8-bit capture register) 
2 channels
Mode 1: 8-bit programmable timer with a programmable prescaler (with an 8-bit capture register) +
8-bit programmable counter (with an 8-bit capture register)
Mode 2: 16-bit programmable timer with a programmable prescaler (with a 16-bit capture register)
Mode 3: 16-bit programmable counter (with a 16-bit capture register)
3.5.2 Functions
1)
Mode 0: 8-bit programmable timer with a programmable prescaler (with an 8-bit capture register)
channels
• Two independent 8-bit programmable timers (T0L and T0H) run on the clock (with a period of
1 to 256 Tcyc) from an 8-bit programmable prescaler.
• The contents of T0L are captured into the capture register T0CAL on external input detection
signals from the P70/INT0/T0LCP, P16/INT2/T0IN, P20, and P21 timer 0L capture input pins.
• The contents of T0H are captured into the capture register T0CAH on external input detection
signals from the P17/INT1/T0HCP, P15/INT3/T0IN, P20, and P21 timer 0H capture input pins.
T0L period = (T0LR + 1)  (T0PRR + 1)  Tcyc
T0H period = (T0HR + 1)  (T0PRR + 1)  Tcyc
Tcyc = Period of cycle clock
2)
Mode 1: 8-bit programmable timer with a programmable prescaler (with an 8-bit capture register) +
8-bit programmable counter (with an 8-bit capture register)
• T0L serves as an 8-bit programmable counter that counts the number of external input
detection signals from the P16/INT2/T0IN and P15/INT3/T0IN pins.
• T0H serves as an 8-bit programmable timer that runs on the clock (with a period of 1 to 256
Tcyc) from an 8-bit programmable prescaler.
• The contents of T0L are captured into the capture register T0CAL on external input detection
signals from the P70/INT0/T0LCP, P16/INT2/T0IN, P20, and P21 timer 0L capture input pins.
• The contents of T0H are captured into the capture register T0CAH on external input detection
signals from the P17/INT1/T0HCP, P15/INT3/T0IN, P20, and P21 timer 0H capture input
pins.
T0L period = (T0LR + 1)
T0H period = (T0HR + 1)  (T0PRR +1)  Tcyc
3-23
T0
3)
Mode 2: 16-bit programmable timer with a programmable prescaler (with a 16-bit capture register)
• Timer/counter 0 serves as a 16-bit programmable timer that runs on the clock (with a period of
1 to 256 Tcyc) from an 8-bit programmable prescaler.
• The contents of T0L and T0H are captured into the capture registers T0CAL and T0CAH at the
same time on external input detection signals from the P17/INT1/T0HCP, P15/INT3/T0IN, P20,
and P21 timer 0H capture input pins.
T0 period = ([T0HR, T0LR] + 1)  (T0PRR +1)  Tcyc
16 bits
4)
Mode 3: 16-bit programmable counter (with a 16-bit capture register)
• Timer/counter 0 serves as a 16-bit programmable counter that counts the number of external
input detection signals from the P16/INT2/T0IN and P15/INT3/T0IN pins.
• The contents of T0L and T0H are captured into the capture registers T0CAL and T0CAH at the
same time on external input detection signals from the P17/INT1/T0HCP, P15/INT3/T0IN,
P20, and P21 timer 0H capture input pins.
T0 period = [T0HR, T0LR] + 1
16 bits
5)
Interrupt generation
T0L or T0H interrupt request is generated at the counter period of T0L or T0H if the interrupt
request enable bit is set.
6)
It is necessary to manipulate the following special function registers to control timer/counter 0 (T0).
• T0CNT, T0PRR, T0L, T0H, T0LR, T0HR, T0CAL, T0CAH
• P7, ISL, I01CR, I23CR
• P2, P2DDR, I45CR, I45SL
Address
Initial Value
R/W
Name
FE10
0000 0000
R/W
T0CNT
T0HRUN T0LRUN T0LONG T0LEXT T0HCMP
BIT7
BIT6
BIT5
FE11
0000 0000
R/W
T0PRR
T0PRR7
T0PRR6
T0PRR5
BIT4
T0PRR4
BIT3
T0PRR3
BIT2
BIT1
BIT0
T0HIE
T0LCMP
T0LIE
T0PRR2
T0PRR1
T0PRR0
FE12
0000 0000
R
T0L
T0L7
T0L6
T0L5
T0L4
T0L3
T0L2
T0L1
T0L0
FE13
0000 0000
R
T0H
T0H7
T0H6
T0H5
T0H4
T0H3
T0H2
T0H1
T0H0
FE14
0000 0000
R/W
T0LR
T0LR7
T0LR6
T0LR5
T0LR4
T0LR3
T0LR2
T0LR1
T0LR0
FE15
0000 0000
R/W
T0HR
T0HR7
T0HR6
T0HR5
T0HR4
T0HR3
T0HR2
T0HR1
T0HR0
FE16
XXXX XXXX
R
T0CAL
T0CAL7 T0CAL6
T0CAL5
T0CAL4
T0CAL3
T0CAL2
T0CAL1
T0CAL0
FE17
XXXX XXXX
R
T0CAH
T0CAH7 T0CAH6 T0CAH5
T0CAH4 T0CAH3 T0CAH2 T0CAH1 T0CAH0
3.5.3 Circuit Configuration
3.5.3.1 Timer/counter 0 control register (T0CNT) (8-bit register)
1)
This register controls the operation and interrupts of T0L and T0H.
3-24
LC87BK00 Chapter 3
3.5.3.2 Programmable prescaler match register (T0PRR) (8-bit register)
1)
This register stores the match data for the programmable prescaler.
3.5.3.3 Programmable prescaler (8-bit counter)
1)
2)
3)
Start/stop:
Count clock:
Match signal:
4)
Reset:
This register runs in modes other than HOLD mode.
Cycle clock (period = 1 Tcyc)
A match signal is generated when the count value matches the value of the
register T0PRR (period: 1 to 256 Tcyc).
The counter starts counting from 0 when a match signal is generated or when
data is written into T0PRR.
3.5.3.4 Timer/counter 0 low byte (T0L) (8-bit counter)
1)
Start/stop:
2)
Count clock:
3)
Match signal:
4)
Reset:
Stop/start is controlled by the 0/1 value of T0LRUN (timer 0 control register, bit
6).
Either a prescaler match signal or an external signal must be selected through the
0/1 value of T0LEXT (timer 0 control register, bit 4).
A match signal is generated when the count value matches the value of the match
buffer register (16 bits of data needs to match in the 16-bit mode).
When the counter stops operation or a match signal is generated.
3.5.3.5 Timer/counter 0 high byte (T0H) (8-bit counter)
1)
Start/stop:
2)
Count clock:
3)
Match signal:
4)
Reset:
Stop/start is controlled by the 0/1 value of T0HRUN (timer 0 control register, bit
7).
Either a prescaler match signal or a T0L match signal must be selected through
the 0/1 value of T0LONG (timer 0 control register, bit 5).
A match signal is generated when the count value matches the value of the match
buffer register (16 bits of data needs to match in the 16-bit mode).
When the counter stops operation or a match signal is generated.
3.5.3.6 Timer/counter 0 match data register low byte (T0LR) (8-bit register with a match buffer
register)
1)
2)
This register is used to store the match data for T0L. It has an 8-bit match buffer register. A match
signal is generated when the value of this match buffer register matches the value of the low-order
byte of timer/counter 0 (16 bits of data needs to match in the 16-bit mode).
The match buffer register is updated as follows:
• When it is inactive (T0LRUN=0), the match buffer register matches T0LR.
• When it is active (T0LRUN=1), the match buffer register is loaded with the contents of T0LR
when a match signal is generated.
3.5.3.7 Timer/counter 0 match data register high byte (T0HR) (8-bit register with a match
buffer register)
1)
2)
This register is used to store the match data for T0H. It has an 8-bit match buffer register. A match
signal is generated when the value of this match buffer register matches the value of the high-order
byte of timer/counter 0 (16 bits of data needs to match in the 16-bit mode).
The match buffer register is updated as follows:
• When it is inactive (T0HRUN=0), the match buffer register matches T0HR.
• When it is active (T0HRUN=1), the match buffer register is loaded with the contents of T0HR
when a match signal is generated.
3-25
T0
3.5.3.8 Timer/counter 0 capture register low byte (T0CAL) (8-bit register)
1)
2)
Capture clock:
Capture data:
External input detection signals from the P70/INT0/T0LCP,
P20, and P21 timer 0L capture input pins when T0LONG
register, bit 5) is set to 0.
External input detection signals from the P17/INT1/T0HCP,
P20, and P21 timer 0H capture input pins when T0LONG
register, bit 5) is set to 1.
Contents of timer/counter 0 low byte (T0L).
P16/INT2/T0IN,
(timer 0 control
P15/INT3/T0IN,
(timer 0 control
3.5.3.9 Timer/counter 0 capture register high byte (T0CAH) (8-bit register)
1)
Capture clock:
2)
Capture data:
External input detection signals from the P17/INT1/T0HCP, P15/INT3/T0IN,
P20, and P21 timer 0H capture input pins.
Contents of timer/counter 0 high byte (T0H).
Table 3.5.1. Timer 0 (T0H, T0L) Count Clocks
Mode T0LONG
0
0
1
0
2
1
3
1
T0LEXT
0
1
0
1
T0H Count Clock
T0PRR match signal
T0PRR match signal
T0L Count Clock
T0PRR match signal
External signal
[T0H, T0L] Count Clock
－
－
－
－
T0PRR match signal
External signal
3-26
－
－
LC87BK00 Chapter 3
Clock
Tcyc
Clear
Prescaler
Match
Capture trigger
Comparator
Registers I01CR(FE5Dh)
I23CR(FE5Eh), ISL(FE5Fh)
I45CR(FE4Ah), and
T0PRR
I45SL(FE4Bh) need setting
T0CAL
T0CAH
Capture
Clock
Capture
Clear
Clock
T0L
Clear
T0H
Match
Comparator
Match
Comparator
Match buffer register
Reload
T0HCMP
flag set
Match buffer register
T0LCMP
flag set
Reload
T0LR
T0HR
8-bit programmable timer
with programmable prescaler
8-bit programmable timer
with programmable prescaler
Figure 3.5.1. Mode 0 Block Diagram (T0LONG =0 , T0LEXT = 0)
Clock
Tcyc
Capture trigger
Registers I01CR(FE5Dh)
I23CR(FE5Eh), ISL(FE5Fh)
I45CR(FE4Ah), and
I45SL(FE4Bh) need setting
Clear
Prescaler
Match
Comparator
T0PRR
T0CAL
External
input
Clock
T0CAH
Capture
Clock
Clear
T0L
Set in register
ISL (FE5Fh)
Clear
T0H
Match
Match
Comparator
Capture
Comparator
Match buffer register
T0LCMP
Reload flag set
T0LR
Match buffer register
Reload
T0HCMP
flag set
T0HR
8-bit programmable timer
with programmable prescaler
8-bit programmable counter
Figure 3.5.2. Mode 1 Block Diagram (T0LONG = 0, T0LEXT = 1)
3-27
T0
Clock
Clear
Prescaler
Tcyc
Match
Comparator
T0PRR
Capture trigger
T0CAH
T0CAL
Registers I01CR(FE5Dh)
I23CR(FE5Eh), ISL(FE5Fh)
Capture
Clock
T0H
Clear
T0L
I45SL(FE4Bh) need setting
Match
Comparator
Match buffer register
Reload
T0HR
I45CR(FE4Ah), and
T0LCMP
T0HCMP
flag set
T0LR
16-bit programmable timer
with programmable prescaler
Figure 3.5.3. Mode 2 Block Diagram (T0LONG = 1, T0LEXT = 0)
Capture trigger
T0CAH
T0CAL
Registers I01CR(FE5Dh)
I23CR(FE5Eh), ISL(FE5Fh)
Capture
External
input
Clock
Clear
T0H
T0L
I45CR(FE4Ah), and
I45SL(FE4Bh) need setting
Set in register
Match
ISL (FE5Fh)
Comparator
Match buffer register
T0HR
T0LCMP
T0HCMP
Reload flag set
T0LR
16-bit programmable counter
Figure 3.5.4. Mode 3 Block Diagram (T0LONG = 1, T0LEXT = 1)
3-28
LC87BK00 Chapter 3
3.5.4 Related Registers
3.5.4.1 Timer/counter 0 control register (T0CNT)
1)
This register is an 8-bit register that controls the operation and interrupts of T0L and T0H.
Address
Initial Value
R/W
Name
FE10
0000 0000
R/W
T0CNT
BIT7
BIT6
BIT5
BIT4
BIT3
T0HRUN T0LRUN T0LONG T0LEXT T0HCMP
BIT2
BIT1
BIT0
T0HIE
T0LCMP
T0LIE
T0HRUN (bit 7): T0H count control
When this bit is set to 0, timer/counter 0 high byte (T0H) stops on a count value of 0. The match buffer
register of T0H has the same value as T0HR.
When this bit is set to 1, timer/counter 0 high byte (T0H) performs the required counting operation. The
match buffer register of T0H is loaded with the contents of T0HR when a match signal is generated.
T0LRUN (bit 6): T0L count control
When this bit is set to 0, timer/counter 0 low byte (T0L) stops on a count value of 0. The match buffer
register of T0L has the same value as T0LR.
When this bit is set to 1, timer/counter 0 low byte (T0L) performs the required counting operation. The
match buffer register of T0L is loaded with the contents of T0LR when a match signal is generated.
T0LONG (bit 5): Timer/counter 0 bit length select
When this bit is set to 0, timer/counter 0 high- and low-order bytes serve as independent 8-bit timers/
counters.
When this bit is set to 1, timer/counter 0 functions as a 16-bit timer/counter. A match signal is generated
when the count value of the 16-bit counter comprising T0H and T0L matches the contents of the match
buffer registers of T0H and T0L.
T0LEXT (bit 4): T0L input clock select
When this bit is set to 0, the count clock for T0L becomes the match signal for the prescaler.
When this bit is set to 1, the count clock for T0L becomes an external input signal.
T0HCMP (bit 3): T0H match flag
This bit is set when the value of T0H matches the value of the match buffer register for T0H and a match
signal is generated while T0H is running (T0HRUN=1). Its state does not change if no match signal is
generated. Consequently, this flag must be cleared with an instruction.
In the 16-bit mode (T0LONG=1), a match needs to occur in all 16 bits of data for a match signal to occur.
T0HIE (bit 2): T0H interrupt request enable control
When this bit and T0HCMP are set to 1, an interrupt request to vector address 0023H is generated.
3-29
T0
T0LCMP (bit 1): T0L match flag
This bit is set when the value of T0L matches the value of the match buffer register for T0L and a match
signal is generated while T0L is running (T0LRUN=1). Its state does not change if no match signal is
generated. Consequently, this flag must be cleared with an instruction.
In the 16-bit mode (T0LONG=1), a match needs to occur in all 16 bits of data for a match signal to occur.
T0LIE (bit 0): T0L interrupt request enable control
When this bit and T0LCMP are set to 1, an interrupt request to vector address 0013H is generated.
Notes:
• T0HCMP and T0LCMP must be cleared to 0 with an instruction.
• When the 16-bit mode is to be used, T0LRUN and T0HRUN must be set to the same value at the same
time to control operation.
• T0LCMP and T0HCMP are set at the same time in the 16-bit mode.
3.5.4.2 Timer 0 programmable prescaler match register (T0PRR)
1)
2)
3)
This register is an 8-bit register used to define the clock period (Tpr) of timer/counter 0.
The count value of the prescaler starts at 0 when T0PRR is loaded with data.
Tpr = (T0PRR+1)  Tcyc
Tcyc = Period of cycle clock
Address
Initial Value
R/W
Name
BIT7
BIT6
BIT5
BIT4
BIT3
BIT2
BIT1
BIT0
FE11
0000 0000
R/W
T0PRR
T0PRR7
T0PRR6
T0PRR5
T0PRR4
T0PRR3
T0PRR2
T0PRR1
T0PRR0
3.5.4.3 Timer/counter 0 low byte (T0L)
1)
This is a read-only 8-bit timer/counter. It counts the number of match signals from the prescaler or
external signals.
Address
Initial Value
R/W
Name
BIT7
BIT6
BIT5
BIT4
BIT3
BIT2
BIT1
BIT0
FE12
0000 0000
R
T0L
T0L7
T0L6
T0L5
T0L4
T0L3
T0L2
T0L1
T0L0
3.5.4.4 Timer/counter 0 high byte (T0H)
1)
This is a read-only 8-bit timer/counter. It counts the number of match signals from the prescaler or
overflow occurring in T0L.
Address
Initial Value
R/W
Name
BIT7
BIT6
BIT5
BIT4
BIT3
BIT2
BIT1
BIT0
FE13
0000 0000
R
T0H
T0H7
T0H6
T0H5
T0H4
T0H3
T0H2
T0H1
T0H0
3.5.4.5 Timer/counter 0 match data register low byte (T0LR)
1)
2)
This register is used to store the match data for T0L. It has an 8-bit match buffer register. A match
signal is generated when the value of this match buffer register matches the value of the low-order
byte of timer/counter 0 (16 bits of data needs to match in the 16-bit mode).
The match buffer register is updated as follows:
• When it is inactive (T0LRUN=0), the match buffer register matches T0LR.
• When it is active (T0LRUN=1), the match buffer register is loaded with the contents of T0LR
when a match signal is generated.
Address
Initial Value
R/W
Name
BIT7
BIT6
BIT5
BIT4
BIT3
BIT2
BIT1
BIT0
FE14
0000 0000
R/W
T0LR
T0LR7
T0LR6
T0LR5
T0LR4
T0LR3
T0LR2
T0LR1
T0LR0
3-30
LC87BK00 Chapter 3
3.5.4.6 Timer/counter 0 match data register high byte (T0HR)
1)
2)
This register is used to store the match data for T0H. It has an 8-bit match buffer register. A match
signal is generated when the value of this match buffer register matches the value of the high-order
byte of timer/counter 0 (16 bits of data needs to match in the 16-bit mode).
The match buffer register is updated as follows:
• When it is inactive (T0HRUN=0), the match buffer register matches T0HR.
• When it is active (T0HRUN=1), the match buffer register is loaded with the contents of T0HR
when a match signal is generated.
Address
Initial Value
R/W
Name
BIT7
BIT6
BIT5
BIT4
BIT3
BIT2
BIT1
BIT0
FE15
0000 0000
R/W
T0HR
T0HR7
T0HR6
T0HR5
T0HR4
T0HR3
T0HR2
T0HR1
T0HR0
3.5.4.7 Timer/counter 0 capture register low byte (T0CAL)
1)
This register is a read-only 8-bit register used to capture the contents of timer/counter 0 low byte
(T0L) on an external input detection signal.
Address
Initial Value
R/W
Name
BIT7
BIT6
BIT5
BIT4
BIT3
BIT2
BIT1
BIT0
FE16
XXXX XXXX
R
T0CAL
T0CAL7
T0CAL6
T0CAL5
T0CAL4
T0CAL3
T0CAL2
T0CAL1
T0CAL0
3.5.4.8 Timer/counter 0 capture register high byte (T0CAH)
1)
This register is a read-only 8-bit register used to capture the contents of timer/counter 0 high byte
(T0H) on an external input detection signal.
Address
Initial Value
R/W
Name
FE17
XXXX XXXX
R
T0CAH
BIT7
BIT6
BIT5
BIT4
BIT3
BIT2
BIT1
BIT0
T0CAH7 T0CAH6 T0CAH5 T0CAH4 T0CAH3 T0CAH2 T0CAH1 T0CAH0
3-31
T1
3.6 Timer/Counter 1 (T1)
3.6.1 Overview
The timer/counter 1 (T1) incorporated in this series of microcontrollers is a 16-bit timer/counter that has
the following four functions:
1)
2)
3)
4)
Mode 0: 8-bit programmable timer with an 8-bit prescaler (with toggle output) + 8-bit programmable
timer/counter with an 8-bit prescaler (with toggle output)
Mode 1: 8-bit PWM with an 8-bit prescaler 2 channels
Mode 2: 16-bit programmable timer/counter with an 8-bit prescaler (with toggle output)
(The low-order 8 bits may be used as a timer/counter with toggle output.)
Mode 3: 16-bit programmable timer with an 8-bit prescaler (with toggle output)
(The low-order 8 bits may be used as a PWM.)
3.6.2 Functions
1)
Mode 0: 8-bit programmable timer with an 8-bit prescaler (with toggle output) + 8-bit programmable
timer/counter with an 8-bit prescaler (with toggle output)
• Two independent 8-bit programmable timers (T1L and T1H) run on a clock that is obtained by
dividing the cycle clock by 2.
• T1L functions as an 8-bit programmable timer/counter that counts the number of signals
obtained by dividing the cycle clock by 2 or external events, while T1H functions as an 8-bit
programmable timer that counts the number of signals obtained by dividing the cycle clock
by 2.
• T1PWML and T1PWMH generate a signal that toggles at the interval of T1L and T1H periods,
respectively. (Note 1)
T1L period = (T1LR + 1)  (T1LPRC count)  2 Tcyc or
(T1LR + 1) (T1LPRC count) events detected
T1PWML period = T1L period 
T1H period = (T1HR + 1)  (T1HPRC count)  2 Tcyc
T1PWMH period = T1H period 
2)
Mode 1: 8-bit PWM with an 8-bit prescaler 2 channels
• Two independent 8-bit PWMs (T1PWML and T1PWMH) run on the cycle clock.
T1PWML period = 256  (T1LPRC count)  Tcyc
T1PWML low period = (T1LR + 1)  (T1LPRC count)  Tcyc
T1PWMH period = 256  (T1HPRC count)  Tcyc
T1PWMH low period = (T1HR + 1)  (T1HPRC count)  Tcyc
3)
Mode 2: 16-bit programmable timer/counter with an 8-bit prescaler (with toggle output)
(The low-order 8 bits may be used as a timer/counter with toggle output.)
• Functions as a 16-bit programmable timer/counter that counts the number of signals obtained
by dividing the cycle clock by 2 or external events. Since interrupts can occur from the
low-order 8-bit timer (T1L) at the interval of T1L period, the low-order 8 bits of this 16-bit
programmable timer/counter can be used as the reference timer.
• T1PWML and T1PWMH generate a signal that toggles at the interval of T1L and T1 periods,
respectively. (Note 1)
3-32
LC87BK00 Chapter 3
T1L period = (T1LR + 1)  (T1LPRC count)  2 Tcyc or
(T1LR + 1) T1LPRC count) events detected
T1PWML period = T1L period 
T1 period = (T1HR + 1)  (T1HPRC count)  T1L period
T1PWMH period = T1 period  2
4)
Mode 3: 16-bit programmable timer with an 8-bit prescaler (with toggle output)
(The low-order 8 bits may be used as a PWM.)
• A 16-bit programmable timer runs on the cycle clock.
• The low-order 8 bits run as a PWM (T1PWML) having a period of 256 Tcyc.
• T1PWMH generates a signal that toggles at the interval of T1 period. (Note 1)
T1PWML period = 256  (T1LPRC count)  Tcyc
T1PWML low period = (T1LR + 1)  (T1LPRC count)  Tcyc
T1 period = (T1HR + 1)  (T1HPRC count)  T1PWML period
T1PWMH period = T1 period  2
5)
Interrupt generation
A T1L or T1H interrupt request is generated at the counter period of T1L or T1H if the interrupt
request enable bit is set.
6)
It is necessary to manipulate the following special function registers to control timer 1 (T1).
• T1CNT, T1PRR, T1L, T1H, T1LR, T1HR
• P1, P1DDR, P1FCR
• P2, P2DDR, I45CR, I45SL
Address
Initial Value
R/W
Name
FE18
0000 0000
R/W
T1CNT
T1HRUN T1LRUN T1LONG T1PWM T1HCMP
BIT7
BIT6
BIT5
BIT4
BIT3
BIT2
BIT1
BIT0
T1HIE
T1LCMP
T1LIE
T1HPRE T1HPRC2 T1HPRC1 T1HPRC0 T1LPRE T1LPRC2 T1LPRC1 T1LPRC0
FE19
0000 0000
R/W
T1PRR
FE1A
0000 0000
R
T1L
FE1B
0000 0000
R
T1H
T1H7
T1H6
T1H5
T1H4
T1H3
T1H2
T1H1
T1H0
FE1C
0000 0000
R/W
T1LR
T1LR7
T1LR6
T1LR5
T1LR4
T1LR3
T1LR2
T1LR1
T1LR0
FE1D
0000 0000
R/W
T1HR
T1HR7
T1HR6
T1HR5
T1HR4
T1HR3
T1HR2
T1HR1
T1HR0
T1L7
T1L6
T1L5
T1L4
T1L3
T1L2
T1L1
T1L0
Note 1: The output of T1PWML is fixed high if T1L is stopped. If T1L is running, the output of T1PWML is fixed
low when T1LR = FFH. The output of T1PWMH is fixed high if T1H is stopped. If T1H is running, the
output of T1PWMH is fixed low when T1HR = FFH.
3-33
T1
3.6.3 Circuit Configuration
3.6.3.1 Timer 1 control register (T1CNT) (8-bit register)
1)
This register controls the operation and interrupts of T1L and T1H.
3.6.3.2 Timer 1 prescaler control register (T1PRR) (8-bit register)
1)
This register sets the clocks for T1L and T1H.
3.6.3.3 Timer 1 prescaler low byte (8-bit counter)
1)
Start/stop:
2)
Count clock:
Stop/start is controlled by the 0/1 value of T1LRUN (timer 1 control register,
bit 6).
Depends on the operating mode.
Mode
0
1
2
3
T1LONG
0
0
1
1
T1PWM
0
1
0
1
T1L Prescaler Count Clock
2 Tcyc/events (Note 1)
1 Tcyc (Note 2)
2 Tcyc/events (Note 1)
1 Tcyc (Note 2)
Note 1: T1L serves as an event counter when INT4 is specified as the timer 1 count clock input in the
external interrupt 4/5 pin select register (I45SL). It serves as a timer that runs on 2Tcyc as its
count clock if INT4 is not specified as the timer 1 count clock input.
Note 2: T1L will not run normally if INT4 is specified as the timer 1 count clock input when T1PWM = 1.
When T1PWM = 1, do not specify INT4 as the timer 1 count clock input.
3)
Prescaler count: Determined by the T1PRR value.
The count clock for T1L is output at intervals determined by the prescaler count.
T1LPRE
0
1
1
1
1
1
1
1
1
4)
Reset:
T1LPRC2
T1LPRC1
T1LPRC0
–
–
–
0
0
0
0
1
1
1
1
0
0
1
1
0
0
1
1
0
1
0
1
0
1
0
1
T1L Prescaler Count
1
2
4
8
16
32
64
128
256
When timer 1 stops operation or a T1L reset signal is generated.
3-34
LC87BK00 Chapter 3
3.6.3.4 Timer 1 prescaler high byte
1)
Start/stop:
2)
Count clock:
Mode
0
1
2
3
3)
Stop/start is controlled by the 0/1 value of T1HRUN (timer 1 control register,
bit 7).
Depends on the operating mode.
T1LONG
0
0
1
1
T1PWM
0
1
0
1
T1H Prescaler Count Clock
2 Tcyc
1 Tcyc
T1L match signal
256 (T1LPRC count) Tcyc
Prescaler count: Determined by the T1PRR value.
The count clock for T1H is output at intervals determined by the prescaler count.
T1HPRE
0
1
1
1
1
1
1
1
1
4)
(8-bit counter)
Reset:
T1HPRC2
T1HPRC1
T1HPRC0
–
–
–
0
0
0
0
1
1
1
1
0
0
1
1
0
0
1
1
0
1
0
1
0
1
0
1
T1H Prescaler Count
1
2
4
8
16
32
64
128
256
When timer 1 stops operation or a T1H reset signal is generated.
3.6.3.5 Timer 1 low byte (T1L) (8-bit counter)
1)
Start/stop:
2)
3)
Count clock:
Match signal:
4)
Reset:
Stop/start is controlled by the 0/1 value of T1LRUN (timer 1 control register,
bit 6).
T1L prescaler output clock
A match signal is generated when the count value matches the value of the match
buffer register.
When the counter stops operation or a match signal occurs in mode 0 or 2.
3.6.3.6 Timer 1 high byte (T1H) (8-bit counter)
1)
Start/stop:
2)
3)
Count clock:
Match signal:
4)
Reset:
Stop/start is controlled by the 0/1 value of T1HRUN (timer 1 control register,
bit 7).
T1H prescaler output clock
A match signal is generated when the count value matches the value of the match
buffer register.
When the counter stops operation or a match signal occurs in mode 0, 2, or 3.
3-35
T1
3.6.3.7 Timer 1 match data register low byte (T1LR) (8-bit register with a match buffer register)
1)
2)
This register is used to store the match data for T1L. It has an 8-bit match buffer register. A match
signal is generated when the value of this match buffer register matches the value of timer 1 low byte
(T1L)
The match buffer register is updated as follows:
• When it is inactive (T1LRUN=0), the match buffer register matches T1LR.
• When it is active (T1LRUN=1), the match buffer register is loaded with the contents of T1LR
when the value of T1L reaches 0.
3.6.3.8 Timer 1 match data register high byte (T1HR) (8-bit register with a match buffer register)
1)
2)
This register is used to store the match data for T1H. It has an 8-bit match buffer register. A match
signal is generated when the value of this match buffer register matches the value of timer 1 high
byte (T1H).
The match buffer register is updated as follows:
• When it is inactive (T1HRUN=0), the match buffer register matches T1HR.
• When it is active (T1HRUN=1), the match buffer register is loaded with the contents of T1HR
when the value of T1H reaches 0.
3.6.3.9 Timer 1 low byte output (T1PWML)
1)
2)
3)
The T1PWML output is fixed high when T1L is inactive. If T1L is active, the T1PWML output is
fixed low when T1LR = FFH.
When T1PWM (timer 1 control register, bit 4) is set to 0, timer 1 low byte output is a toggle output
whose state changes on a T1L match signal.
When T1PWM (timer 1 control register, bit 4) is set to 1, timer 1 low byte output is a PWM output
that is cleared on a T1L overflow and set on a T1L match signal.
3.6.3.10 Timer 1 high byte output (T1PWMH)
1)
2)
3)
The T1PWMH output is fixed high when T1H is inactive. If T1H is active, the T1PWMH output is
fixed low when T1HR = FFH.
When T1PWM = 0 or T1LONG = 1, the timer 1 high byte output is a toggle output whose state
changes on a T1H match signal.
When T1PWM = 1 and T1LONG = 0, timer 1 high byte output is a PWM output that is cleared on a
T1H overflow and set on a T1H match signal.
3-36
LC87BK00 Chapter 3
2Tcyc
Clock
or
external events
Set in
I45CR(FE4Ah)
I45SL(FE4Bh) Clock
registers
Clock
2Tcyc
T1L prescaler
Clock
Clear
T1L
Match
Comparator
T1H prescaler
Invert
Clear
T1H
Match
Comparator
T1PWML
output
Invert
T1PWMH
output
Match buffer
register
Match buffer
register
Reload
Reload
T1LCMP
flag set
T1LR
T1HCMP
flag set
T1HR
8-bit programmable
timer/counter
8-bit programmable timer
Figure 3.6.1. Mode 0 Block Diagram (T1LONG = 0, T1PWM = 0)
Clock
1Tcyc
Clock
1Tcyc
T1L prescaler
Clock
T1L
Overflow
Match
Comparator
Reset
T1H prescaler
Clock
T1PWML
output
Set
Match buffer
register
Match
Comparator
Reset
T1PWMH
output
Set
Match buffer
register
Reload
Reload
T1LR
Overflow
T1H
T1LCMP
flag set
8-bit PWM
T1HR
8-bit PWM
Figure 3.6.2. Mode 1 Block Diagram (T1LONG = 0, T1PWM = 1)
3-37
T1HCMP
flag set
T1
2Tcyc
Clock
or
external events
Set in
I45CR(FE4Ah)
I45SL(FE4Bh) Clock
registers
Clock
T1L prescaler
Clock
Clear
T1L
Comparator
T1H prescaler
Clear
T1H
Match
Invert
Comparator
Match
T1PWML
output
Invert
T1PWMH
output
Match buffer
register
Match buffer
register
Reload
Reload
T1LCMP
flag set
T1LR
T1HCMP
flag set
T1HR
16-bit programmable
timer/counter
Figure 3.6.3. Mode 2 Block Diagram (T1LONG = 1, T1PWM = 0)
Clock
1Tcyc
Clock
T1L prescaler
Clock
T1L
Comparator
T1H prescaler
Overflow
Match
Reset
Clock
Clear
T1H
T1PWML
output
Comparator
Set
Match buffer
register
Invert
T1PWMH
output
Match buffer
register
Reload
T1LR
Match
Reload
T1LCMP
flag set
T1HR
16-bit programmable timer
Figure 3.6.4. Mode 3 Block Diagram (T1LONG = 1, T1PWM = 1)
3-38
T1HCMP
flag set
LC87BK00 Chapter 3
3.6.4 Related Registers
3.6.4.1 Timer 1 control register (T1CNT)
1)
This register is an 8-bit register that controls the operation and interrupts of T1L and T1H.
Address
Initial Value
R/W
Name
FE18
0000 0000
R/W
T1CNT
BIT7
BIT6
BIT5
T1HRUN T1LRUN T1LONG
BIT4
BIT3
BIT2
BIT1
BIT0
T1PWM
T1HCMP
T1HIE
T1LCMP
T1LIE
T1HRUN (bit 7): T1H count control
When this bit is set to 0, timer 1 high byte (T1H) stops on a count value of 0. The match buffer register of
T1H has the same value as T1HR.
When this bit is set to 1, timer 1 high byte (T1H) performs the required counting operation.
T1LRUN (bit 6): T1L count control
When this bit is set to 0, timer 1 low byte (T1L) stops on a count value of 0. The match buffer register of
T1L has the same value as T1LR.
When this bit is set to 1, timer 1 low byte (T1L) performs the required counting operation.
T1LONG (bit 5): Timer 1 bit length select
When this bit is set to 0, timer 1 high- and low-order bytes serve as independent 8-bit timers.
When this bit is set to 1, timer 1 serves as a 16-bit timer since the timer 1 high byte (T1H) counts up at the
interval of the timer 1 low byte (T1L).
Independent match signals are generated from T1H and T1L when their count value matches the contents
of the corresponding match buffer register, regardless of the value of this bit.
T1PWM (bit 4): T1 output mode select
This bit and T1LONG (bit 5) determine the output mode of T1 (T1PWMH and T1PWML) as summarized
in Table 3.6.1.
Table 3.6.1. Timer 1 Output (T1PWMH, T1PWML)
Mode T1LONG T1PWM
T1PWMH
T1PWML
0
0
0
Toggle
output
Period:(T1HR+1)  (T1HPRC count)  2Tcyc 
Toggle
output
or
1
0
1
Period: 256  (T1HPRC count)  Tcyc
2
1
0
PWM
output
Toggle
output
or
PWM
output
Toggle
output
or
3
1
1
Toggle
output
Period: {(T1HR+1)  (T1HPRC count)  (T1LR+1)
(T1LPRC count)  2 Tcyc} 
Period: {(T1HR+1)  (T1HPRC count)  (T1LR+1)
 (T1LPRC count) events} 
Period: {(T1HR+1)  (T1HPRC count)  256 
(T1LPRC count) Tcyc} 2
T1HCMP (bit 3): T1H match flag
This flag is set if T1H reaches 0 when T1H is active (T1HRUN = 1).
This flag must be cleared with an instruction.
3-39
PWM
output
Period: {(T1LR+1)  (T1LPRC count)
 2Tcyc}  2
Period: {(T1LR+1)  (T1LPRC count)
events} 
Period: 256  (T1LPRC count)  Tcyc
Period: {(T1LR+1)  (T1LPRC count)
 2Tcyc} 2
Period: {(T1LR+1)  (T1LPRC count)
events} 
Period: 256  (T1LPRC count)  Tcyc
T1
T1HIE (bit 2): T1H interrupt request enable control
An interrupt request is generated to vector address 002BH when this bit and T1HCMP are set to 1.
T1LCMP (bit 1): T1L match flag
This flag is set if T1L reaches 0 when T1L is active (T1LRUN = 1).
This flag must be cleared with an instruction.
T1LIE (bit 0): T1L interrupt request enable control
An interrupt request is generated to vector address 002BH when this bit and T1LCMP are set to 1.
Note: T1HCMP and T1LCMP must be cleared to 0 with an instruction.
3.6.4.2
1)
2)
Timer 1 prescaler control register (T1PRR)
This register sets the count values for the timer 1 prescaler.
When the register value is changed while the timer is running, the change is reflected in the prescaler
operation at the same timing when the match buffer register for the timer (T1L, T1H) is updated.
Address
Initial Value
R/W
Name
FE19
0000 0000
R/W
T1PRR
BIT7
BIT6
BIT5
BIT4
BIT3
T1HPRE T1HPRC2 T1HPRC1 T1HPRC0 T1LPRE
BIT2
BIT1
T1LPRC2 T1LPRC1 T1LPRC0
T1HPRE (bit 7): Timer 1 prescaler high byte control
T1HPRC2 (bit 6): Timer 1 prescaler high byte control
T1HPRC1 (bit 5): Timer 1 prescaler high byte control
T1HPRC0 (bit 4): Timer 1 prescaler high byte control
T1HPRE
0
1
1
1
1
1
1
1
1
T1HPRC2
T1HPRC1
T1HPRC0
–
–
–
0
0
0
0
1
1
1
1
0
0
1
1
0
0
1
1
0
1
0
1
0
1
0
1
T1LPRE (bit 3): Timer 1 prescaler low byte control
T1LPRC2 (bit 2): Timer 1 prescaler low byte control
T1LPRC1 (bit 1): Timer 1 prescaler low byte control
T1LPRC0 (bit 0): Timer 1 prescaler low byte control
3-40
BIT0
T1H Prescaler Count
1
2
4
8
16
32
64
128
256
LC87BK00 Chapter 3
T1LPRE
0
1
1
1
1
1
1
1
1
T1LPRC2
T1LPRC1
T1LPRC0
–
–
–
0
0
0
0
1
1
1
1
0
0
1
1
0
0
1
1
0
1
0
1
0
1
0
1
T1L Prescaler Count
1
2
4
8
16
32
64
128
256
3.6.4.3 Timer 1 low byte (T1L)
1)
This is a read-only 8-bit timer. It counts up on the T1L prescaler output clock.
Address
Initial Value
R/W
Name
BIT7
BIT6
BIT5
BIT4
BIT3
BIT2
BIT1
BIT0
FE1A
0000 0000
R
T1L
T1L7
T1L6
T1L5
T1L4
T1L3
T1L2
T1L1
T1L0
3.6.4.4 Timer 1 high byte (T1H)
1)
This is a read-only 8-bit timer. It counts up on the T1H prescaler output clock.
Address
Initial Value
R/W
Name
BIT7
BIT6
BIT5
BIT4
BIT3
BIT2
BIT1
BIT0
FE1B
0000 0000
R
T1H
T1H7
T1H6
T1H5
T1H4
T1H3
T1H2
T1H1
T1H0
3.6.4.5 Timer 1 match data register low byte (T1LR)
1)
2)
This register is used to store the match data for T1L. It has an 8-bit match buffer register. A match
signal is generated when the value of this match buffer register matches the value of timer 1 low
byte.
The match buffer register is updated as follows:
• When it is inactive (T1LRUN=0), the match buffer register matches T1LR.
• When it is active (T1LRUN=1), the match buffer register is loaded with the contents of T1LR
when the value of T1L reaches 0.
Address
Initial Value
R/W
Name
BIT7
BIT6
BIT5
BIT4
BIT3
BIT2
BIT1
BIT0
FE1C
0000 0000
R/W
T1LR
T1LR7
T1LR6
T1LR5
T1LR4
T1LR3
T1LR2
T1LR1
T1LR0
3.6.4.6 Timer 1 match data register high byte (T1HR)
1)
2)
This register is used to store the match data for T1H. It has an 8-bit match buffer register. A match
signal is generated when the value of this match buffer register matches the value of timer 1 high
byte.
The match buffer register is updated as follows:
• When it is inactive (T1HRUN=0), the match buffer register matches T1HR.
• When it is active (T1HRUN=1), the match buffer register is loaded with the contents of T1HR
when the value of T1H reaches 0.
Address
Initial Value
R/W
Name
BIT7
BIT6
BIT5
BIT4
BIT3
BIT2
BIT1
BIT0
FE1D
0000 0000
R/W
T1HR
T1HR7
T1HR6
T1HR5
T1HR4
T1HR3
T1HR2
T1HR1
T1HR0
3-41
T1
Match buffer register value
Modes 0, 2
T1L,T1H
Match signal
Interrupt flag set
T1PWML,T1PWMH
Figure 3.6.5. Modes 0, 2 Operating Waveform Example
Counter value=FFH
Mode 1
Match
T1L, T1H
Match signal
Counter value=FFH
Interrupt flag set
T1PWML,T1PWMH
Figure 3.6.6. Mode 1 Operating Waveform Example
3-42
LC87BK00 Chapter 3
Match buffer register value
Mode 3
T1H
Match signal
Interrupt flag set
T1PWMH
Counter value=FFH
Match
T1L
Match signal
Counter value=FFH
Interrupt flag set
T1PWML
Figure 3.6.7. Mode 3 Operating Waveform Example
3-43
T6, T7
3.7 Timers 6 and 7 (T6, T7)
3.7.1 Overview
Timer 6 (T6) and timer 7 (T7) incorporated in this series of microcontrollers are 8-bit timers with two
independently controlled 6-bit prescalers.
3.7.2 Functions
1)
Timer 6 (T6)
Timer 6 is an 8-bit timer that runs on a 4 Tcyc, 16 Tcyc, or 64 Tcyc clock. It can generate toggle
waveforms at pin P06 whose frequency is equal to the period of timer 6.
T6 period = (T6R+1) 4ｎTcyc (n=1, 2, 3)
Tcyc = Period of cycle clock
2)
Timer 7 (T7)
Timer 7 is an 8-bit timer that runs on a 4 Tcyc, 16 Tcyc, or 64 Tcyc clock. It can generate toggle
waveforms at pin P07 whose frequency is equal to the period of timer 7.
T7 period = (T7R+1)  4ｎTcyc (n=1, 2, 3)
Tcyc = Period of cycle clock
3)
Interrupt generation
An interrupt request to vector address 0043H is generated when the overflow flag is set at the
interval of timer 6 or timer 7 period and the corresponding interrupt request enable bit is set.
4)
It is necessary to manipulate the following special function registers to control timer 6 (T6) and timer
7 (T7).
• T67CNT, T6R, T7R, P0FCR
Address
Initial Value
R/W
Name
BIT7
BIT6
BIT5
BIT4
BIT3
BIT2
BIT1
BIT0
FE78
0000 0000
R/W
T67CNT
T7C1
T7C0
T6C1
T6C0
T7OV
T7IE
T6OV
T6IE
FE7A
0000 0000
R/W
T6R
T6R7
T6R6
T6R5
T6R4
T6R3
T6R2
T6R1
T6R0
FE7B
0000 0000
R/W
T7R
T7R7
T7R6
T7R5
T7R4
T7R3
T7R2
T7R1
T7R0
FE42
00HH 0000
R/W
P0FCR
T7OE
T6OE
-
-
CLKOEN CKODV2 CKODV1 CKODV0
3.7.3 Circuit Configuration
3.7.3.1 Timer 6/7 control register (T67CNT) (8-bit register)
1)
This register controls the operation and interrupts of T6 and T7.
3.7.3.2 Timer 6 counter (T6CTR) (8-bit counter)
1)
2)
3)
This counter counts the number of clocks from the timer 6 prescaler (T6PR). The value of the timer
6 counter (T6CTR) reaches 0 on the clock following the clock that reaches the value specified in the
timer 6 period setting register (T6R), when the interrupt flag (T6OV) is set.
When T6C0 and T6C1 (T67CNT: FE78, bits 4 and 5) are set to 0, the timer 6 counter stops at a
count value of 0. In other cases, the timer 6 counter continues operation.
When data is written into T6R while timer 6 is running, both the timer 6 prescaler and counter are
cleared and start counting again.
3-44
LC87BK00 Chapter 3
3.7.3.3 Timer 6 prescaler (T6PR) (6-bit counter)
1)
This prescaler is used to define the clock period for timer 6 with the value of T6C0 and T6C1.
(T67CNT: FE78, bits 4 and 5).
Table 3.7.1. Timer 6 Count Clocks
T6C1
0
0
1
1
T6C0
0
1
0
1
T6 Count Clock
Timer 6 prescaler and timer/counter are in the reset state.
4 Tcyc
16 Tcyc
64 Tcyc
3.7.3.4 Timer 6 period setting register (T6R) (8-bit register)
1)
2)
This register defines the period of timer 6.
When data is written into T6R while timer 6 is running, both the timer 6 prescaler and counter are
cleared and start counting again.
3.7.3.5 Timer 7 counter (T7CTR) (8-bit counter)
1)
2)
3)
This counter counts the number of clocks from the timer 7 prescaler (T7PR). The value of the timer
7 counter (T7CTR) reaches 0 on the clock following the clock that reaches the value specified in the
timer 7 period setting register (T7R), when the interrupt flag (T7OV) is set.
When T7C0 and T7C1 (T67CNT: FE78, bits 6 and 7) are set to 0, the timer 7 counter stops at a
count value of 0. In other cases, the timer 7 counter continues operation.
When data is written into T7R while timer 7 is running, both the timer 7 prescaler and counter are
cleared and start counting again.
3.7.3.6 Timer 7 prescaler (T7PR) (6-bit counter)
1)
This prescaler is used to define the clock period for timer 7 with the value of T7C0 and T7C1
(T67CNT: FE78, bits 6 and 7).
Table 3.7.2. Timer 7 Count Clocks
T7C1
0
0
1
1
T7C0
0
1
0
1
T7 Count Clock
Timer 7 prescaler and timer/counter are in the reset state.
4 Tcyc
16 Tcyc
64 Tcyc
3.7.3.7 Timer 7 period setting register (T7R) (8-bit register)
1)
2)
This register defines the period of timer 7.
When data is written into T7R while timer 7 is running, both the timer 7 prescaler and counter are
cleared and start counting again.
3-45
T6, T7
Timer 6 period setting register
T6R(FE7Ah)
Timer 6/7 control register
T67CNT(FE78h)
bit5
T6 overflow
(T6R+1)  count clock
bit4
Comparator
Set prescaler
count value
1Tcyc
Clock
Timer 6 prescaler
(T6PR)
Clock
Timer 6 counter
(T6CTR)
Clear
Clear
Timer 6/7 control register
T67CNT(FE78h)
bit3
bit2
Set
bit1
bit0
Set
T6 interrupt
T7 interrupt
Clear
1Tcyc
Clock
Timer 7 prescaler
(T7PR)
Clear
Clock
Timer 7 counter
(T7CTR)
Set prescaler
count value
bit7
bit6
Comparator
T7 overflow
(T7R+1)  count clock
Timer 6/7 control register
T67CNT(FE78h)
Timer 7 period setting register
T7R(FE7Bh)
Figure 3.7.1. Timer 6/7 Operation Block Diagram
3-46
LC87BK00 Chapter 3
3.7.4 Related Registers
3.7.4.1 Timer 6/7 control register (T67CNT)
1)
This register is an 8-bit register that controls the operation and interrupts of T6 and T7.
Address
Initial Value
R/W
Name
BIT7
BIT6
BIT5
BIT4
BIT3
BIT2
BIT1
BIT0
FE78
0000 0000
R/W
T67CNT
T7C1
T7C0
T6C1
T6C0
T7OV
T7IE
T6OV
T6IE
T7C1 (bit 7): T7 count clock control
T7C0 (bit 6): T7 count clock control
T7C1
0
0
1
1
T7C0
0
1
0
1
T7 Count Clock
Timer 7 prescaler and timer/counter are stopped in the reset state.
4 Tcyc
16 Tcyc
64 Tcyc
T6C1 (bit 5): T6 count clock control
T6C0 (bit 4): T6 count clock control
T6C1
0
0
1
1
T6C0
0
1
0
1
T6 Count Clock
Timer 6 prescaler and timer/counter are stopped in the reset state.
4 Tcyc
16 Tcyc
64 Tcyc
T7OV (bit 3): T7 overflow flag
This flag is set at the interval of the timer 7 period when timer 7 is running.
This flag must be cleared with an instruction.
T7IE (bit 2): T7 interrupt request enable control
An interrupt request to vector address 0043H is generated when this bit and T7OV are set to 1.
T6OV (bit 1): T6 overflow flag
This flag is set at the interval of the timer 6 period when timer 6 is running.
This flag must be cleared with an instruction.
T6IE (bit 0): T6 interrupt request enable control
An interrupt request to vector address 0043H is generated when this bit and T6OV are set to 1.
3.7.4.2 Timer 6 period setting register (T6R)
1)
2)
This register is an 8-bit register for defining the period of timer 6.
Timer 6 period = (T6R value+1)  Timer 6 prescaler value
(4, 16 or 64 Tcyc)
When data is written into T6R while timer 6 is running, both the timer 6 prescaler and counter are
cleared and start counting again.
Address
Initial Value
R/W
Name
BIT7
BIT6
BIT5
BIT4
BIT3
BIT2
BIT1
BIT0
FE7A
0000 0000
R/W
T6R
T6R7
T6R6
T6R5
T6R4
T6R3
T6R2
T6R1
T6R0
3-47
T6, T7
3.7.4.3 Timer 7 period setting register (T7R)
1)
2)
This register is an 8-bit register for defining the period of timer 7.
Timer 7 period = (T7R value+1)  Timer 7 prescaler value
(4, 16 or 64 Tcyc)
When data is written into T7R while timer 7 is running, both the timer 7 prescaler and counter are
cleared and start counting again.
Address
Initial Value
R/W
Name
BIT7
BIT6
BIT5
BIT4
BIT3
BIT2
BIT1
BIT0
FE7B
0000 0000
R/W
T7R
T7R7
T7R6
T7R5
T7R4
T7R3
T7R2
T7R1
T7R0
3.7.4.4 Port 0 function control register (P0FCR)
1)
P0FCR is a 6-bit register used to control the multiplexed output of port 0 pins. It controls the toggle
outputs of timers 6 and 7.
Address
Initial Value
R/W
Name
BIT7
BIT6
BIT5
BIT4
FE42
00HH 0000
R/W
P0FCR
T7OE
T6OE
-
-
BIT3
BIT2
BIT1
BIT0
CLKOEN CKODV2 CKODV1 CKODV0
T7OE (bit 7):
This bit is used to control the timer 7 toggle output at pin P07.
This bit is disabled when P07 is in input mode.
When P07 is in output mode:
0: Carries the value of the port data latch.
1: Carries the OR of the waveform that toggles at the interval of the timer 7 period and the value of the
port data latch.
T6OE (bit 6):
This bit is used to control the timer 6 toggle output at pin P06.
This bit is disabled when P06 is in input mode.
When P06 is in output mode:
0: Carries the value of the port data latch.
1: Carries the OR of the waveform that toggles at the interval of the timer 6 period and the value of the
port data latch.
(Bits 5, 4): These bits do not exist.
They are always read as 1.
CLKOEN (bit 3):
CKODV2 (bit 2):
CKODV1 (bit 1):
CKODV0 (bit 0):
These 4 bits have nothing to do with the control functions of timers 6 and 7. See the description of port 0
for details on these bits.
3-48
LC87BK00 Chapter 3
3.8
Base Timer (BT)
3.8.1 Overview
The base timer (BT) incorporated in this series of microcontrollers is a 14-bit binary up-counter that has
the following five functions:
1)
2)
3)
4)
5)
Clock timer
14-bit binary up-counter
High-speed mode (when used as a 6-bit base timer)
Buzzer output
X’tal HOLD mode release
3.8.2 Functions
1)
Clock timer
The base timer can count clocks at 0.5 second intervals when a 32.768 kHz subclock is used as the
count clock for the base timer. In this case, one of the three clocks, i.e., cycle clock, timer/counter 0
prescaler output, and subclock, must be selected by the input signal select register (ISL) as the base
timer count clock.
2)
14-bit binary up-counter
A 14-bit binary up-counter can be constructed using an 8-bit binary up-counter and a 6-bit binary
up-counter. These counters can be cleared under program control.
3)
High-speed mode (when used as a 6-bit base timer)
When the base timer is used as a 6-bit timer, it can clock at intervals of approximately 2 ms if the
32.768 kHz subclock is used as the count clock. The bit length change can be specified using the
base timer control register (BTCR).
4)
Buzzer output function
The base timer can generate a 2 kHz buzzer output when the 32.768 kHz subclock is used as the
count clock. The buzzer output can be controlled using the input signal select register (ISL). The
buzzer output can be transmitted via pin P17.
5)
Interrupt generation
An interrupt request to vector address 001BH is generated if an interrupt request is generated by the
base timer when the interrupt request enable bit is set. The base timer can generate two types of
interrupt requests: base timer interrupt 0 and base timer interrupt 1.
6)
X’tal HOLD mode operation and X’tal HOLD mode release function
The base timer is enabled for operation in X’tal HOLD mode when bit 2 of the power control register
(PCON) is set. X’tal HOLD mode can be released by an interrupt from the base timer. This function
allows the microcontroller to perform low-current intermittent operations.
3-49
BT
7)
It is necessary to manipulate the following special function registers to control the base timer.
• BTCR, ISL, P1, P1DDR, P1FCR
Address
Initial Value
R/W
Name
BIT7
BIT6
BIT5
BIT4
BIT3
BIT2
BIT1
BIT0
FE7F
0000 0000
R/W
BTCR
BTFST
BTON
BTC11
BTC10
BTIF1
BTIE1
BTIF0
BTIE0
FE5F
0000 0000
R/W
ISL
ST0HCP
ST0LCP
BUZON
NFSEL
NFON
ST0IN
BTIMC1 BTIMC0
3.8.3 Circuit Configuration
3.8.3.1 8-bit binary up-counter
1)
This counter is an up-counter that receives, as its input, the signal selected by the input signal select
register (ISL). It generates a 2 kHz buzzer output and base timer interrupt 1 flag set signals. The
overflow from this counter serves as the clock for the 6-bit binary counter.
3.8.3.2 6-bit binary up-counter
1)
This counter is a 6-bit up-counter that receives, as its input, the signal selected by the input signal
select register (ISL) or the overflow signal from the 8-bit counter. It generates base timer interrupt
0/1 set signals. The switching of the input clock is accomplished by the base timer control register
(BTCR).
3.8.3.3 Base timer input clock source
1)
The clock input to the base timer can be selected from among the cycle clock, timer/counter 0
prescaler output, and subclock by the input signal select register (ISL).
Set in
ISL(FE5Fh)
register
16tBST
Buzzer output
Timer 0 prescaler
Selector
Tcyc
1tBST
8-bit counter
Subclock
6-bit counter
16384/64tBST
BTIF0 flag set
32tBST
128tBST
512/2tBST
2048/8tBST
Figure 3.8.1. Base Timer Block Diagram
3-50
Selector
Selector
256tBST
BTIF1 flag set
LC87BK00 Chapter 3
3.8.4 Related Registers
3.8.4.1 Base timer control register (BTCR)
1)
The register is an 8-bit register that controls the operation of the base timer.
Address
Initial Value
R/W
Name
BIT7
BIT6
BIT5
BIT4
BIT3
BIT2
BIT1
BIT0
FE7F
0000 0000
R/W
BTCR
BTFST
BTON
BTC11
BTC10
BTIF1
BTIE1
BTIF0
BTIE0
BTFST (bit 7): Base timer interrupt 0 period control
This bit is used to select the interval at which base timer interrupt 0 is to occur.
When this bit is set to 1, the base timer interrupt 0 flag is set when an overflow occurs in the 6-bit counter.
The interval at which overflows occur is 64tBST.
When this bit is set to 0, the base timer interrupt 0 flag is set when an overflow occurs in the 14-bit counter.
The interval at which overflows occur is 16384tBST.
This bit must be set to 1 when high-speed mode is to be used.
tBST: The period of the input clock to the base timer selected by the input signal select register (ISL),
bits 5 and 4
BTON (bit 6): Base timer operation control
When this bit is set to 0, the base timer stops when the count value reaches 0.
When this bit is set to 1, the base timer continues operation.
BTC11 (bit 5): Base timer interrupt 1 period control
BTC10 (bit 4): Base timer interrupt 1 period control
BTFST
BTC11
BTC10
0
１
0
１
0
0
1
1
0
0
0
0
1
1
1
1
0
0
1
1
0
1
0
1
Base Timer Interrupt 0
Period
16384tBST
64tBST
16384tBST
64tBST
16384tBST
16384tBST
64tBST
64tBST
Base Timer Interrupt 1
Period
32tBST
32tBST
128tBST
128tBST
512tBST
2048tBST
2tBST
8tBST
BTIF1 (bit 3): Base timer interrupt 1 flag
This flag is set at the interval of the base timer interrupt 1 period that is defined by BTFST, BTC11, and
BTC10.
This flag must be cleared with an instruction.
BTIE1 (bit 2): Base timer interrupt 1 request enable control
Setting this bit and BTIF1 to 1 generates an X'tal HOLD mode release signal and an interrupt request to
vector address 001BH.
BTIF0 (bit 1): Base timer interrupt 0 flag
This flag is set at the interval of the base timer interrupt 0 period that is defined by BTFST, BTC11, and
BTC10.
This flag must be cleared with an instruction.
BTIE0 (bit 0): Base timer interrupt 0 request enable control
Setting this bit and BTIF0 to 1 generates an X'tal HOLD mode release signal and an interrupt request to
vector address 001BH.
3-51
BT
Notes:
• Set the conditions under which the flags (BTIF1 and BTIF0) are set at intervals of the base timer
interrupt period so that the period of the cycle clock (Tcyc) and the base timer interrupt period satisfy
the following relationship:
Period of cycle clock (Tcyc)＜ Base timer interrupt period ÷ 2
Since program processing (e.g., interrupt processing routine) is involved in practice, the time that is
required to execute such processing should be taken into consideration when setting up the optimum
interrupt period.
• Note that there are cases BTIF1 is set to 1 if BTC11 or BTC10 is rewritten when the base timer is active.
• If the crystal oscillator (subclock) is selected as the base timer clock source, erroneous counting may
occur in the base timer because oscillation stabilization time cannot be secured when HOLD mode is
exited. It is therefore recommended that measures be taken to stop the base timer before placing the
CPU in HOLD mode. (See Section 4.2, "System Clock Generator Function," for the state of the
oscillator circuits in standby mode.)
• Counting errors may occur in the base timer if the base timer clock source is changed (change ISL, bits
5 and 4) while the base timer is running. Be sure to stop the base timer in advance when changing the
base timer clock source.
3.8.4.2 Input signal select register (ISL)
1)
This register is an 8-bit register that is used to control the timer 0 input, noise filter time constant, to
select buzzer output/timer 1 PWMH output, and to select base timer clock.
Address
Initial Value
R/W
Name
BIT7
BIT6
FE5F
0000 0000
R/W
ISL
ST0HCP
ST0LCP
BIT5
BIT4
BTIMC1 BTIMC0
BIT3
BIT2
BIT1
BIT0
BUZON
NFSEL
NFON
ST0IN
ST0HCP (bit 7): Timer 0H capture signal input port select
ST0LCP (bit 6): Timer 0L capture signal input port select
These 2 bits have nothing to do with the control function of the base timer.
BTIMC1 (bit 5): Base timer clock select
BTIMC0 (bit 4): Base timer clock select
BTIMC1
0
0
1
1
BTIMC0
0
1
0
1
Base Timer Input Clock
Subclock
Cycle clock
Subclock
Timer/counter 0 prescaler output
BUZON (bit 3): Buzzer output/timer 1 PWMH output select
This bit selects data (buzzer output or timer 1 PWMH) to be transferred to P17 when P17FCR (P1FCR, bit
7) is set to 1.
When this bit is set to 1, the timer 1 PWMH output is fixed high and the signal that is obtained by
frequency-dividing the base timer clock by 16 (fBST/16) is sent to P17 as the buzzer output.
When this bit is set to 0, the buzzer output is fixed high and the timer 1 PWMH output data is sent to P17.
fBST: The frequency of the input clock to the base timer selected by the input signal select register
(ISL), bits 5 and 4
NFSEL (bit 2): Noise filter time constant select
NFON (bit 1): Noise filter time constant select
ST0IN (bit 0): Timer 0 count clock input port select
These 3 bits have nothing to do with the control function of the base timer.
3-52
LC87BK00 Chapter 3
3.9 Serial Interface 1 (SIO1)
3.9.1 Overview
The serial interface 1 (SIO1) incorporated in this series of microcontrollers has the following four
functions:
1)
2)
3)
4)
Mode 0: Synchronous 8-bit serial I/O (2- or 3-wire system, 2 to 512 Tcyc transfer clock)
Mode 1: Asynchronous serial (half-duplex, 8 data bits, 1 stop bit, 8 to 2048 Tcyc baudrate)
Mode 2: Bus-master (start bit, 8 data bits, 2 to 512 Tcyc transfer clock)
Mode 3: Bus-slave (start detection, 8 data bits, stop detection)
3.9.2 Functions
1)
Mode 0: Synchronous 8-bit serial I/O
• Performs 2- or 3-wire synchronous serial communication. The clock may be an internal or
external clock.
• The period of the internal clock is programmable within the range of 2 to 512 Tcyc.
2)
Mode 1: Asynchronous serial (UART)
• Performs half-duplex, 8 data bits, 1 stop bit asynchronous serial communication.
• The baudrate is programmable within the range of 8 to 2048 Tcyc.
3)
Mode 2: Bus-master
• SIO1 is used as a bus master controller.
• The start conditions are automatically generated, but the stop conditions must be generated by
manipulating ports.
• Clock synchronization is used. Since it is possible to verify the transfer-time bus data at the end
of transfer, this mode can be combined with mode 3 to provide support for multi-master
configurations.
• The period of the output clock is programmable within the range of 2 to 512 Tcyc.
4)
Mode 3: Bus-slave
• SIO1 is used as a slave device of the bus.
• Start/stop condition detection processing is performed but the detection of an address match
condition and the output of acknowledge require program intervention.
• SIO1 can generate an interrupt by forcing the clock line to a low level on the falling edge of the
8th clock for recognition by a program.
5)
Interrupt generation
An interrupt request is generated at the end of communication if the interrupt request enable bit is
set.
6)
It is necessary to manipulate the following special function registers to control the serial interface 1
(SIO1).
• SCON1, SBUF1, SBR1
• P1, P1DDR, P1FCR
Address
Initial Value
R/W
Name
BIT8
BIT7
BIT6
FE34
0000 0000
R/W
SCON1
-
SI1M1
SI1M0
FE35
00000 0000
R/W
SBUF1 SBUF18 SBUF17 SBUF16 SBUF15 SBUF14 SBUF13 SBUF12 SBUF11 SBUF10
FE36
0000 0000
R/W
SBR1
-
BIT5
BIT4
BIT3
BIT2
BIT1
SI1RUN SI1REC SI1DIR SI1OVR SI1END
BIT0
SI1IE
SBRG17 SBRG16 SBRG15 SBRG14 SBRG13 SBRG12 SBRG11 SBRG10
3-53
SIO1
3.9.3 Circuit Configuration
3.9.3.1 SIO1 control register (SCON1) (8-bit register)
1)
This register controls the operation and interrupts of SIO1.
3.9.3.2 SIO1 shift register (SIOSF1) (8-bit shift register)
1)
2)
This register is a shift register used to transfer and receive SIO1 data.
This register cannot be directly accessed with an instruction. It is accessed via SBUF1.
3.9.3.3 SIO1 data register (SBUF1) (9-bit register)
1)
2)
The low-order 8 bits of SBUF1 are transferred to SIOSF1 at the beginning of data transfer.
At the end of data transfer, the contents of SIOSF1 are placed in the low-order 8 bits of SBUF1. In
modes 1, 2, and 3, since the 9th input data is placed in bit 8 of SBUF1, it is possible to check for a
stop bit, etc.
3.9.3.4 SIO1 baudrate generator (SBR1) (8-bit reload counter)
1)
2)
This is a reload counter for generating internal clocks.
The generator can generate clocks of 2 to 512 Tcyc in modes 0 and 2, and clocks of 8 to 2048 Tcyc
in mode 1.
3-54
LC87BK00 Chapter 3
Table 3.9.1. SIO1 Operations and Operating Modes
Synchronous (Mode 0) UART (Mode 1)
Bus Master (Mode 2)
Bus Slave (Mode 3)
Transfer
SI1REC=0
Receive
SI1REC=1
Transfer
SI1REC=0
Receive
SI1REC=1
Transfer
SI1REC=0
Transfer
SI1REC=0
Receive
SI1REC=1
Start bit
None
None
Output
(Low)
Input
(Low)
See 1) and 2) Not required
below
Not required
See 2) below
Data output
8
8
(Shift data) (All 1’s)
8
(Shift data)
8
(All 1’s)
8
(Shift data)
8
(All 1’s)
Data input
8
(Input pin)

8
(Input pin)

8
(Input pin)

8
(Input pin)

Stop bit
None

Output
(High)
Input
(H/L)
Input
(H/L)
Output
Input
(SBUF1,bit8) (H/L)
Output
(L)
Clock
8

9
(Internal)

9


Operation start
SI1RUN↑ 
Period
2 to 512
Tcyc
SI1RUN
(bit 5)
SI1END
(bit 1)
8
8
(Shift data) (All 1’s)
1)
Start bit
SI1RUN↑ detected
2)
Start bit
detected
Receive
SI1REC=1
Low output
on falling
edge of 8th
clock
1)
1) on left side 1) on right
No start bit
side
on falling
edge of
SI1END
when
SI1RUN=1
2)
With start bit
on rising
edge of
SI1RUN
when
SI1END=0
1)
Clock
released on
falling edge
of SI1END
when
SI1RUN=1
2)
Start bit
detected
when
SI1RUN=0
and
SI1END=0

8 to 2048
Tcyc

2 to 512Tcyc 
2 to 512Tcyc 
Set Instruction

1)
Instruction
2)
Start bit
detected
Start bit
detected
Instruction
Already set
Already set
Start bit
detected
Clear End of
processing

End of stop 
bit

1)
Stop
condition
detected
2)
Ack=1
detected

Set End of
processing

End of stop 
bit
1)
Stop
condition
detected
2)
When
arbitration
lost (Note 1)
1)
Rising edge
of 9th clock
2)
Stop
condition
detected

1)
Falling edge
of 8th clock
2)
Stop
condition
detected

Clear Instruction

Instruction
Instruction

Instruction


Note 1: If internal data output value = H and data port value = L are detected on the rising edges of the 1st to
8th clocks, the CPU recognizes a bus contention loss and clears SI1RUN (and also stops sending the
clock at the same time).
(Continued on next page)
3-55
SIO1
Table 3.9.1. SIO1 Operations and Operating Modes (cont.)
SI1OVR Set
(bit 2)
Synchronous (Mode 0) UART (Mode 1)
Bus Master (Mode 2)
Bus Slave (Mode 3)
Transfer
SI1REC=0
Transfer
SI1REC=0
Receive
SI1REC=1
Transfer
SI1REC=0
Receive
SI1REC=1
1)
SI1END set
conditions
met when
SI1END=1


Instruction

1)
Falling edge
of clock
detected
when
SI1RUN=0
2)
SI1END set
conditions
met when
SI1END=1
3)
Start bit
detected
Instruction
Receive
SI1REC=1

SBUF1→

shifter at
beginning
of operation
Rising edge 
of 8th clock
Shifter data
update
Shifter
SBUF1
(bits 0 to 7)
Automatic data None
update of
SBUF1, bit 8
Receive
SI1REC=1

1)
Falling edge
of clock
detected
when
SI1RUN=0
2)
SI1END set
conditions
met when
SI1END=1

1)
Falling edge
of clock
detected
when
SI1RUN=0
2)
SI1END set
conditions
met when
SI1END=1
Clear Instruction
Transfer
SI1REC=0

Instruction

SBUF1→
shifter at
beginning
of operation
When 8-bit
data
transferred
Input data
read in on
stop bit

SBUF1→

shifter at
beginning of
operation
When 8-bit Rising edge 
data
of 8th clock
received

Input data

read in on
rising edge of
9th clock

SBUF1→

shifter at
beginning of
operation
Rising edge 
of 8th clock
Input data

read in on
rising edge of
9th clock
Data input
8-bit shift register(SIOSF1)
Data
output
Clock
At time
transfer ends
At time
operation
starts
bit7 bit6 bit5 bit4 bit3 bit2 bit1 bit0
SBUF1(FE35h)
SIO1 output control
P13 port latch
P13 output control
P13
SIO1 output control
P14 port latch
P14
P14 output control
Clock
Clock generator
circuit
Baudrate
generator
SIO1 output control
P15
P15 port latch
P15 output control
MSB/LSB first select
Serial transfer end flag
SBR1(FE36h) Overrun flag
bit7 bit6 bit5 bit4 bit3 bit2 bit1 bit0
SCON1(FE34h)
Interrupt request
Figure 3.9.1. SIO1 Mode 0: Synchronous 8-bit Serial I/O Block Diagram (SI1M1=0, SI1M0=0)
3-56
LC87BK00 Chapter 3
Start bit
additional
circuit
Shift input
Shift input
8-bit shift register (SIOSF1)
Start, stop bit
additional circuit
At time 8-bit
transfer
ends
Shift clock
At time operation starts
LSB, MSB
first select
Stop bit data input
bit8
bit7 bit6 bit5 bit4 bit3 bit2 bit1 bit0
SBUF1 (FE35h)
Stop bit input clock
SIO1 output control
P13 port latch
P13 output control
P13
SIO1 output control
P14 port latch
P14 output control
P14
BUS
Clock generator
circuit
Baudrate
generator
SBR1 (FE36h)
Set SI1END when
stop bit data ends
Overrun flag
bit7 bit6 bit5 bit4 bit3 bit2 bit1 bit0
SCON1 (FE34h)
Interrupt request
Figure 3.9.2. SIO1 Mode 1: Asynchronous Serial [UART] Block Diagram (SI1M1=0, SI1M0=1)
3-57
SIO1
3.9.4 SIO1 Communication Examples
3.9.4.1 Synchronous serial communication (mode 0)
1)
Setting the clock
• Set up SBR1 when using an internal clock.
2)
Setting the mode
• Set as follows:
SI1M0=0, SI1M1=0, SI1DIR, SI1IE=1
3)
Setting up the ports and SI1REC (bit 4)
Internal clock
External clock
Clock Port
P15
Output
Input
Data transmission only
Data reception only
Data transmission/reception (3-wire)
Data Output Port
P13
Output
–
Output
Data transmission/reception (2-wire)
–
Data I/O Port
P14
–
Input
Input
N-channel open
drain output
SI1REC
0
1
0
0
4)
Setting up output data
• Write output data into SBUF1 in the data transmission mode (SI1REC=0).
5)
Starting operation
• Set SI1RUN.
6)
Reading data (after an interrupt)
• Read SBUF1 (SBUF1 has been loaded with serial data from the data I/O port even in transmission
mode).
• Clear SI1END and exit interrupt processing.
• Return to step 4) to repeat operation.
3.9.4.2 Asynchronous serial communication (mode 1)
1)
Setting the baudrate
• Set up SBR1.
2)
Setting the mode
• Set as follows:
SI1M0=1, SI1M1=0, SI1DIR, SI1IE=1
3)
Setting up the ports
Data transmission/reception
(2-wire)
Data transmission/reception
(1-wire)
Data Output Port
P13
Data I/O Port
P14
Output
Input
–
N-channel open drain output
3-58
LC87BK00 Chapter 3
4)
Starting transmit operation
• Set SI1REC to 0 and load SBUF1with output data.
• Set SI1RUN.
Note: Use the SIO1 data I/O port (P14) when using the SIO1 transmission only in mode 1.
In mode 1, transmission is automatically started when a falling edge of receive data is detected.
While mode 1 is on, the falling edge of data is always detected at the data I/O port (P14).
Consequently, if the transmission port is assigned to the data output port (P13), it is likely that
data transmission is started unexpectedly according to the changes in the state of P14.
5)
Starting receive operation
• Set SI1REC to 1. (Once SI1REC is set to 1, do not attempt to write data to the SCON1 register
until the SI1END flag is set.)
• Detect the falling edge of receive data.
6)
Reading data (after an interrupt)
• Read SBUF1. (SBUF1 has been loaded with serial data from the data I/O port even in
transmission mode. When SBUF1 is read in, the data on the position of the stop bit is read into
bit 1 of the PSW.)
• Clear SI1END and exit interrupt processing.
• Return to step 4) to repeat operation.
Note: Make sure that the following conditions are met when performing continuous receive operation in
mode 1 (UART):
• The number of stop bits is set to 2 or greater.
• Clearing of SI1END during interrupt processing terminates before the next start bit arrives.
3.9.4.3 Bus-master mode (mode 2)
1)
Setting the clock
• Set up SBR1.
2)
Setting the mode
• Set as follows:
SI1M0=0, SI1M1=1, SI1DIR, SI1IE=1, SI1REC=0
3)
Setting up the ports
• Configure the clock port (P15) and data port (P14) as N-channel open drain output ports by
setting the option.
• Set P14 (P1, bit 4) and P15 (P1, bit 5) to 0.
• Set P14FCR (P1FCR, bit 4) and P15FCR (P1FCR, bit 5) to 1.
• Set P14DDR (P1DDR, bit 4) and P15DDR (P1DDR, bit 5) to 1.
4)
Starting communication (sending an address)
• Load SBUF1 with address data.
• Set SI1RUN (transfer a start bit + SBUF1 (8 bits) + stop bit (H)).
3-59
SIO1
5)
Checking address data (after an interrupt)
• Read SBUF1. (SBUF1 has been loaded with serial data from the data I/O port even in
transmission mode. When SBUF1 is read in, the data on the position of the stop bit is read into
bit 1 of the PSW.)
• Check for an acknowledge by reading bit 1 of the PSW.
• If a condition for losing the bus contention occurs (see Note 1 in Table 3.9.1), no interrupt will
be generated as SI1RUN is cleared in that case. If there is a possibility of a condition for losing
the bus contention, for example, when another device in master mode is in the system, perform
timeout processing using the timer module, etc. to detect the condition.
6)
Transmitting data
• Load SBUF1 with output data.
• Clear SI1END and exit interrupt processing (transfer SBUF1 (8 bits) + stop bit (H)).
7)
Checking transmission data (after an interrupt)
• Read SBUF1. (SBUF1 has been loaded with serial data from the data I/O port even in
transmission mode. When SBUF1 is read in, the data on the position of the stop bit is read into
bit 1 of the PSW.)
• Check for an acknowledge by reading bit 1 of the PSW.
• If a condition for losing the bus contention occurs (see Note 1 in Table 3.9.1), no interrupt will
be generated as SI1RUN is cleared in that case. If there is a possibility of a condition for losing
the bus contention, for example, when another device in master mode is in the system, perform
timeout processing using the timer module, etc. to detect the condition.
• Return to step 6) to continue data transmission.
• Go to step 10) to terminate communication.
8)
Receiving data
• Set SI1REC to 1.
• Clear SI1END and exit interrupt processing (receive (8 bits) + output SBUF1, bit 8
(acknowledge)).
9)
Reading received data (after an interrupt)
• Read SBUF1.
• Return to step 8) to continue data reception.
• Go to * in step 10) to terminate communication. At this moment SBUF1, bit 8 has already been
output as acknowledge data and the clock for the master side has been released.
10)
Terminating communication
• Manipulate the clock output port (P15FCR=0, P15DDR=1, P15=0) and set the clock output to 0.
• Manipulate the data output port (P14FCR=0, P14DDR=1, P14=0) and set the data output to 0.
• Restore the clock output port to the original state (P15FCR=1, P15DDR=1, P15=0) and release
the clock output.
* • Wait for all slaves to release the clock and the clock to be set to 1.
• Secure a data setup time, then manipulate the data output port (P14FCR=0, P14DDR=1,
P14=1) and set the data output to 1. In this case, the SIO1 overrun flag SI1OVR (SCON1:FE34,
bit 2) is set but this will exert no influence on the operation of SIO1.
• Restore the data output port to the original state (set P14FCR to 1, then P14DDR to 1 and P14
to 0).
• Clear SI1END and SI1OVR, then exit interrupt processing.
• Return to step 4) to repeat operation.
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LC87BK00 Chapter 3
3.9.4.4 Bus-slave mode (mode 3)
1)
Setting the clock
• Set up SBR1 (to set the acknowledge data setup time).
2)
Setting the mode
• Set as follows:
SI1M0=1, SI1M1=1, SI1DIR, SI1IE=1, SI1REC=0
3)
Setting up ports
• Configure the clock port (P15) and data port (P14) as N-channel open drain output ports by
setting the option.
• Set P14 (P1, bit 4) and P15 (P1, bit 5) to 0.
• Set P14FCR (P1FCR, bit 4) and P15FCR (P1FCR, bit 5) to 1.
• Set P14DDR (P1DDR, bit 4) and P15DDR (P1DDR, bit 5) to 1.
4)
Starting communication (waiting for an address)
*1 • Set SI1REC.
*2 • SI1RUN is automatically set on detection of a start bit.
• Perform a receive operation (8 bits), then set the clock output to 0 on the falling edge of the 8th
clock, after which an interrupt occurs.
5)
Checking address data (after an interrupt)
• When a start condition is detected, SI1OVR is set. Check SI1RUN=1 and SI1OVR=1 to
determine if the address has been received.
(SI1OVR is not automatically cleared. Clear it by software.)
• Read SBUF1 and check the address.
• If no address match occurs, clear SI1RUN and SI1END and exit interrupt processing, then wait
for a stop condition detection at * in step 8).
6)
Receiving data
* • Clear SI1END and exit interrupt processing. (If a receive sequence has been performed, send
an acknowledge and release the clock port after the lapse of (SBR1 value + 1/3) × Tcyc.)
• When a stop condition is detected, SI1RUN is automatically cleared and an interrupt is
generated. Then, clear SI1END to exit interrupt processing and return to *2 in step 4).
• Perform a receive operation (8 bits), then set the clock output to 0 on the falling edge of the 8th
clock, after which an interrupt occurs. However, the clock counter is cleared if a start condition
is detected in the middle of receive processing, in which case another 8 clocks are required to
generate an interrupt.
• Read SBUF1 and store the read data.
Note: Bit 8 of SBUF1 is not yet updated because the rising edge of the 9th clock has not yet
occurred.
• Return to * in step 6) to continue receive processing.
7)
Transamitting data
• Clear SI1REC.
• Load SBUF1 with output data.
• Clear SI1END and exit interrupt processing. (Send an acknowledge for the preceding receive
operation and release the clock port after the lapse of (SBR1 value + 1/3) × Tcyc.)
3-61
SIO1
*1 • Perform a transmit operation (8 bits) and set the clock output to 0 on the falling edge of the 8th
clock, after which an interrupt occurs.
*2 • Go to *3 in step 7) if SI1RUN is set to 1.
• If SI1RUN is set to 0, implying an interrupt from *4 in step 7), clear SI1END and SI1OVR and
return to *1 in step 4).
*3 • Read SBUF1 and check transmission data as required.
Note: Bit 8 of SBUF1 is not yet updated because the rising edge of the 9th clock has not yet
occurred.
• Load SBUF1 with the next output data.
• Clear SI1END and exit interrupt processing. (Release the clock port after the lapse of (SBR1
value + 1/3) × Tcyc.)
• Return to *1 in step 7) if an acknowledge from the master is present (L).
• If there is no acknowledge from the master (H), SIO1, recognizing the end of data transmission,
automatically clears SI1RUN and releases the data port.
* However, if the restart condition occurs just after the event, SI1REC must be set to 1 before
exiting the interrupt (SI1REC is for detecting a start condition and is not set automatically).
It may disturb the transmission of address from the master if there is an unexpected restart just
after the slave transmission (when SI1REC is not set to 1 by software).
*4 • When a stop condition is detected, an interrupt is generated and processing returns to *2 in step
7).
8)
3.9.5
Terminating communication
• Set SI1REC.
• Return to * in step 6) to automatically terminate communication.
• To force communication to terminate, clear SI1RUN and SI1END (release the clock port).
* • An interrupt occurs when a stop condition is detected. Then, clear SI1END and SI1OVR and
return to *2 in step 4).
Related Registers
3.9.5.1 SIO1 control register (SCON1)
1)
This register is an 8-bit register that controls the operation and interrupts of SIO1.
Address Initial Value
FE34
0000 0000
R/W
Name
BIT8
BIT7
BIT6
R/W
SCON1
-
SI1M1
SI1M0
BIT5
BIT4
SI1RUN SI1REC
BIT3
SI1M1 (bit 7): SIO1 mode control
SI1M0 (bit 6): SIO1 mode control
Table 3.9.2. SIO1 Operating Modes
Mode
0
1
2
3
SI1M1
0
0
1
1
SI1M0
0
1
0
1
Operating Mode
Synchronous 8-bit SIO
UART (1 stop bit, no parity)
Bus master mode
Bus slave mode
3-62
BIT2
BIT1
SI1DIR SI1OVR SI1END
BIT0
SI1IE
LC87BK00 Chapter 3
SI1RUN (bit 5): SIO1 operation flag
<1> A 1 in this bit indicates that SIO1 is running.
<2> See Table 3.9.1 for the conditions for setting and clearing this bit.
SI1REC (bit 4): SIO1 receive/transmit control
<1> Setting this bit to 1 places SIO1 into reception mode.
<2> Setting this bit to 0 places SIO1 into transmission mode.
SI1DIR (bit 3): MSB/LSB first select
<1> A 1 in this bit selects MSB first.
<2> A 0 in this bit selects LSB first
SI1OVR (bit 2): SIO1 overrun flag
<1> This bit is set when the falling edge of the input clock is detected with SI1RUN =0 in modes 0, 1,
and 3.
<2> This bit is set if the conditions for setting SI1END are established when SI1END=1.
<3> In mode 3 this bit is set when the start condition is detected.
<4> This bit must be cleared with an instruction.
SI1END (bit 1): Serial transfer end flag
<1> This bit is set when serial transfer terminates (see Table 3.9.1).
<2> This bit must be cleared with an instruction.
SI1IE (bit 0): SIO1 interrupt request enable control
<1> When this bit and SI1END are set to 1, an interrupt request to vector address 003BH is generated.
3.9.5.2 Serial buffer 1 (SBUF1)
1)
2)
3)
Serial buffer 1 is a 9-bit register used to store data to be handled during SIO1 serial transfer.
The low-order 8 bits of SBUF1 are transferred to the data shift register for data transmission/
reception at the beginning of transfer processing, and the contents of the shift register are placed in
the low-order 8 bits of SBUF1 when 8-bit data is transferred.
In modes 1, 2, and 3, bit 8 of SBUF1 is loaded with the 9th data (data on the position of the stop bit)
that is received.
Address Initial Value
FE35
00000 0000
R/W
Name
R/W
SBUF1
BIT8
BIT7
BIT6
BIT5
BIT4
BIT3
BIT2
BIT1
BIT0
SBUF18 SBUF17 SBUF16 SBUF15 SBUF14 SBUF13 SBUF12 SBUF11 SBUF10
3.9.5.3 Baudrate generator register (SBR1)
1)
2)
3)
This register is an 8-bit register that defines the baudrate of SIO1 serial transfer. (modes 0, 1, and 2)
Loading this register with data causes the baudrate generating counter to be initialized immediately.
The baudrate varies from mode to mode.
Modes 0 and 2: TSBR1 = (SBR1 value + 1)  2 Tcyc
(Value range = 2 to 512 Tcyc)
Mode 1:
TSBR1 = (SBR1 value + 1)  8 Tcyc
(Value range = 8 to 2048 Tcyc)
3-63
SIO1
4)
When in mode 3, the register sets the acknowledge data setup time (See 3.9.4.4 6), 7)).
When setting to mode 3, time that clock port is released after SI1END is cleared is
(SBR1 value + 1/3)  Tcyc (SBR1=0 is inhibited)
Set this value to meet the opponent device’s data setup time.
Address Initial Value
FE36
0000 0000
R/W
Name
BIT8
R/W
SBR1
-
BIT7
BIT6
BIT5
BIT4
BIT3
BIT2
BIT1
BIT0
SBRG17 SBRG16 SBRG15 SBRG14 SBRG13 SBRG12 SBRG11 SBRG10
3-64
LC87BK00 Chapter 3
3.10
3.10.1
AD Converter (ADC12)
Overview
This series of microcontrollers incorporates a 12-bit resolution AD converter that has the features listed
below. It allows the microcontroller to capture analog signals easily.
1)
2)
3)
4)
5)
3.10.2
12-bit resolution
Successive approximation
AD conversion mode selection (resolution switching)
8-channel analog input
Conversion time selection
Functions
1)
Successive approximation
• The AD converter has a resolution of 12 bits.
• Some conversion time is required after starting conversion processing.
• The conversion results are transferred to the AD conversion result registers (ADRLC, ADRHC).
2)
AD conversion mode selection (resolution switching)
The AD converter supports two AD conversion modes (12- and 8-bit conversion modes), so that the
appropriate conversion resolution can be selected according to the operating conditions of the
application. The AD mode register (ADMRC) is used to select the AD conversion mode.
3)
8-channel analog input
The signal to be converted is selected using the AD control register (ADCRC) from 8 types of
analog signals that are supplied from P00 to P06 and P70.
4)
Conversion time selection
The AD conversion time can be set from 1/1 to 1/128 (frequency division ratio). The AD mode
register (ADMRC) and AD conversion result register low byte (ADRLC) are used to select the
conversion time for appropriate AD conversion.
5)
It is necessary to manipulate the following special function registers to control the AD converter.
• ADCRC, ADMRC, ADRLC, ADRHC
Address
Initial Value
R/W
Name
FE58
0000 0000
R/W
ADCRC
BIT7
BIT6
BIT5
BIT4
AD
AD
AD
AD
CHSEL3 CHSEL2 CHSEL1 CHSEL0
ADMD4
BIT1
AD
ENDF
BIT0
ADIE
FE59
0000 0000
R/W
ADMRC
ADMD1
ADMD0
ADMR2
ADTM1
ADTM0
0000 0000
R/W
ADRLC DATAL3 DATAL2 DATAL1 DATAL0
ADRL3
ADRL2
ADRL1
ADTM2
FE5B
0000 0000
R/W
ADRHC
DATA3
DATA2
DATA1
DATA0
DATA6
ADMD2
ADCR3
BIT2
AD
START
FE5A
DATA7
ADMD3
BIT3
DATA5
3-65
DATA4
ADC12
3.10.3
Circuit Configuration
3.10.3.1
AD conversion control circuit
1)
This circuit runs in two modes: 12- and 8-bit AD conversion modes.
3.10.3.2
1)
Comparator circuit
The comparator circuit consists of a comparator that compares the analog input with the reference
voltage and a control circuit that controls the reference voltage generator circuit and the conversion
results. The conversion end flag (ADENDF) of the AD control register (ADCRC) is set when an
analog input channel is selected and the AD conversion terminates in the conversion time designated
by the conversion time control register. The conversion results are stored in the AD conversion result
registers (ADRHC, ADRLC).
3.10.3.3
1)
Multiplexer 1 (MPX1)
Multiplexer 1 is used to select the analog signal to be subject to AD conversion from 8 channels.
3.10.4
Related Registers
3.10.4.1
AD control register (ADCRC)
1)
This register is an 8-bit register that controls the operation of the AD converter.
Address
FE58
Initial Value
0000 0000
ADCHSEL3 (bit 7):
ADCHSEL2 (bit 6):
ADCHSEL1 (bit 5):
ADCHSEL0 (bit 4):
R/W
R/W
Name
ADCRC
BIT7
BIT6
BIT5
BIT4
AD
AD
AD
AD
CHSEL3 CHSEL2 CHSEL1 CHSEL0
BIT3
BIT2
BIT1
BIT0
ADCR3
AD
START
AD
ENDF
ADIE
AD conversion input signal select
These 4 bits are used to select the signal to be subject to AD conversion.
ADCHSEL3 ADCHSEL2 ADCHSEL1 ADCHSEL0
0
0
0
0
0
0
0
1
0
0
1
0
0
0
1
1
0
1
0
0
0
1
0
1
0
1
1
0
1
0
0
0
ADCR3 (bit 3): Fixed bit
This bit must always be set to 0.
3-66
Signal Input Pin
P00/AN0
P01/AN1
P02/AN2
P03/AN3
P04/AN4
P05/AN5
P06/AN6
P70/AN8
LC87BK00 Chapter 3
ADSTART (bit 2): AD converter operation control
This bit starts (1) or stops (0) AD conversion processing. Setting this bit to 1 starts AD conversion. The bit
is automatically reset when the AD conversion ends. The amount of time specified by the conversion time
control register is required to complete the conversion. The conversion time is defined using three bits, i.e.,
the ADTM2 (bit 0) of the AD conversion result register low byte (ADRLC) and the ADTM1 (bit 1) and
ADTM0 (bit 0) of the AD mode register (ADMRC).
Setting this bit to 0 stops the AD conversion. No correct conversion results can be obtained if this bit is
cleared when AD conversion is in progress.
Never clear this bit while AD conversion is in progress.
ADENDF (bit 1): AD conversion end flag
This bit identifies the end of AD conversion. It is set (1) when AD conversion is completed. Then an
interrupt request to vector address 0043H is generated if ADIE is set to 1. If ADENDF is set to 0, it
indicates that no AD conversion is in progress.
This flag must be cleared with an instruction.
ADIE (bit 0): AD conversion interrupt request enable control
An interrupt request to vector address 0043H is generated when this bit and ADENDF are set to 1.
Notes:
• Setting ADCHSEL3 to ADCHSEL0 to ‘0111’ and between ‘1001’ and ‘1111’ is prohibited.
• Do not place the microcontroller in HOLD mode with ADSTART set to 1. Make sure that ADSTART is
set to 0 before putting the microcontroller in HOLD mode.
• Since the digital input buffer for the analog input channel AN8 of P70 is always open, a through
current will flow through the analog channel when the analog voltage is fed.
If through current is a problem, for operations other than AD conversion, keep the pins at either VDD
or VSS level via an external circuit or use the analog input channels AN0 to AN6 of which the digital
input buffer is closed.
3-67
ADC12
3.10.4.2 AD mode register (ADMRC)
1)
This register is an 8-bit register that controls the operating mode of the AD converter.
Address
Initial Value
R/W
Name
BIT7
BIT6
BIT5
BIT4
BIT3
BIT2
BIT1
BIT0
FE59
0000 0000
R/W
ADMRC
ADMD4
ADMD3
ADMD2
ADMD1
ADMD0
ADMR2
ADTM1
ADTM0
ADMD4 (bit 7): Fixed bit
This bit must always be set to 0.
ADMD3 (bit 6): AD conversion mode control (resolution switching)
This bit selects the AD converter resolution between 12-bit AD conversion mode (0) and 8-bit AD
conversion mode (1).
When this bit is set to 1, the AD converter operates as an 8-bit AD converter. The conversion results are
placed only in the AD conversion result register high byte (ADRHC) and the contents of the AD
conversion result register low byte (ADRLC) remain unchanged.
When this bit is set to 0, the AD converter operates as a 12-bit AD converter. The conversion results are
placed in the AD conversion result register high byte (ADRHC) and the high-order 4 bits of the AD
conversion result register low byte (ADRLC).
ADMD2 (bit 5): Fixed bit
This bit must always be set to 0.
ADMD1 (bit 4): Fixed bit
This bit must always be set to 0.
ADMD0 (bit 3): Fixed bit
This bit must always be set to 0.
ADMR2 (bit 2): Fixed bit
This bit must always be set to 0.
ADTM1 (bit 1):
AD conversion time control
ADTM0 (bit 0):
These bits and ADTM2 (bit 0) of the AD conversion result register low byte (ADRLC) define the
conversion time.
ADRLC
Register
ADTM2
0
0
0
0
1
1
1
1
ADMRC Register
ADTM1
0
0
1
1
0
0
1
1
ADTM0
0
1
0
1
0
1
0
1
3-68
AD Frequency Division Ratio
1/1
1/2
1/4
1/8
1/16
1/32
1/64
1/128
LC87BK00 Chapter 3
Conversion time calculation formulas
• 12-bit AD conversion mode:
Conversion time = ((52/(AD division ratio)) + 2)(1/3)Tcyc
• 8-bit AD conversion mode:
Conversion time = ((32/(AD division ratio)) + 2)(1/3) Tcyc
Notes:
• The conversion time is doubled in the following cases:
<1>The AD conversion is carried out in the 12-bit AD conversion mode for the first time after a system
reset.
<2>The AD conversion is carried out for the first time after the AD conversion mode is switched from 8-bit
to 12-bit AD conversion mode.
• The conversion time determined by the above formula is required in the second and subsequent conversions
or in AD conversions that are carried out in the 8-bit AD conversion mode.
3.10.4.3
1)
2)
AD conversion result register low byte (ADRLC)
This register is used to hold the low-order 4 bits of the results of an AD conversion carried out in the
12-bit AD conversion mode and to control the conversion time.
Since the data in this register is not established during an AD conversion, the conversion results must
be read out only after the AD conversion is completed.
Address
Initial Value
R/W
Name
FE5A
0000 0000
R/W
ADRLC
DATAL3 (bit 7):
DATAL2 (bit 6):
DATAL1 (bit 5):
DATAL0 (bit 4):
BIT7
BIT6
BIT5
BIT4
DATAL3 DATAL2 DATAL1 DATAL0
BIT3
BIT2
BIT1
BIT0
ADRL3
ADRL2
ADRL1
ADTM2
Low-order 4 bits of AD conversion results
ADRL3 (bit 3): Fixed bit
This bit must always be set to 0.
ADRL2 (bit 2): Fixed bit
This bit must always be set to 0.
ADRL1 (bit 1): Fixed bit
This bit must always be set to 0.
ADTM2 (bit 0): AD conversion time control
This bit and ADTM1 (bit 1) and ADTM0 (bit 0) of the AD mode register (ADMRC) are used to control
the conversion time. See the subsection on the AD mode register for the procedure to set up the conversion
time.
Note:
The conversion result data contains errors (quantization error + combination error). Be sure to use only the
valid conversion results based on the specifications provided in the latest "Semiconductor Data Sheet.”
3.10.4.4
1)
2)
AD conversion result register high byte (ADRHC)
This register is used to hold the high-order 8 bits of the results of an AD conversion that is carried
out in the 12-bit AD conversion mode. The register holds the entire 8 bits of the results of an AD
conversion that is carried out in 8-bit AD conversion mode.
Since the data in this register is not established during an AD conversion, the conversion results must
be read out only after the AD conversion is completed.
Address
Initial Value
R/W
Name
BIT7
BIT6
BIT5
BIT4
BIT3
BIT2
BIT1
BIT0
FE5B
0000 0000
R/W
ADRHC
DATA7
DATA6
DATA5
DATA4
DATA3
DATA2
DATA1
DATA0
3-69
ADC12
3.10.5
AD Conversion Example
3.10.5.1
12-bit AD conversion mode
1)
Setting up the 12-bit AD conversion mode
• Set ADMD3 (bit 6) of the AD mode register (ADMRC) to 0.
2)
Setting up the conversion time
• To set the conversion time to 1/32 frequency division ratio, set ADTM2 (bit 0) of the AD
conversion result register low byte (ADRLC) to 1, ADTM1 (bit 1) of the AD mode register
(ADMRC) to 0, and ADTM0 (bit 0) of the AD mode register (ADMRC) to 1.
3)
Setting up the input channel
• When using AD channel input AN5, set the AD control register (ADCRC): ADCHSEL3 (bit 7) to
0, ADCHSEL2 (bit 6) to 1, ADCHSEL1 (bit 5) to 0, and ADCHSEL0 (bit 4) to 1.
4)
Starting AD conversion
• Set ADSTART (bit 2) of the AD control register (ADCRC) to 1.
• The conversion time is doubled when the AD conversion is carried out for the first time after a
system reset or after the AD conversion mode is switched from 8-bit to 12-bit AD conversion
mode. The conversion time determined by the formula is required in the second and subsequent
conversions.
5)
Checking the AD conversion end flag
• Monitor ADENDF (bit 1) of the AD control register (ADCRC) until it is set to 1.
• Clear the conversion end flag (ADENDF) to 0 after confirming that ADENDF (bit 1) is set to 1.
6)
Reading the AD conversion results
• Read the AD conversion result register high byte (ADRHC) and AD conversion result register low
byte (ADRLC). Since the conversion result data contains errors (quantization error + combination
error), use only the valid conversion results based on the specifications provided in the latest
"Semiconductor Data Sheet.”
• Send the above read data to application software processing.
• Return to step 4) to repeat conversion processing.
3-70
LC87BK00 Chapter 3
3.10.6
Hints on the Use of the ADC
1)
The conversion time that the user can select varies depending on the frequency of the cycle clock.
When preparing a program, refer to the latest edition of "Semiconductor Data Sheet" to select an
appropriate conversion time.
2)
Setting ADSTART to 0 while conversion is in progress will stop the conversion function.
3)
Do not place the microcontroller in HOLD mode while AD conversion processing is in progress.
Make sure that ADSTART is set to 0 before putting the microcontroller in HOLD mode.
4)
ADSTART is automatically reset and the AD converter stops operation if a reset is triggered while
AD conversion processing is in progress.
5)
When conversion is finished, the AD conversion end flag (ADENDF) is set and, at the same time,
the AD conversion operation control bit (ADSTART) is reset. The end of conversion processing can
be identified by monitoring ADENDF. Setting ADIE causes an interrupt request to vector address
0043H to be generated at the end of conversion.
6)
The conversion time is doubled in the following cases:
• The AD conversion is carried out in the 12-bit AD conversion mode for the first time after a
system reset.
• The AD conversion is carried out for the first time after the AD conversion mode is switched from
8-bit to 12-bit AD conversion mode.
The conversion time determined by the formula given in the paragraph entitled "Conversion time
calculation formulas" is required in the second and subsequent conversions or in AD conversions
that are carried out in the 8-bit AD conversion mode.
7)
The conversion result data contains some errors (quantization error + combination error). Be sure to
use only valid conversion results based on the specifications provided in the latest "Semiconductor
Data Sheet.”
8)
Make sure that only input voltages that fall within the specified range are supplied to P00/AN0 to
P06/AN6, and P70/AN8. Application of a voltage higher than VDD or lower than VSS to an input
pin may exert an adverse influence on the conversion value of the channel in question or of other
channels.
9)
Take the following measures to prevent a reduction in conversion accuracy due to noise
interferences, etc.:
• Add external bypass capacitors (several µF + thousands of pF) near the VDD1 and VSS1 pins (as
close as possible, desirably 5 mm or less).
• Add external low-pass filters (RC) or capacitors, most suitable for noise reduction, very close to
the analog input pins. To avoid any adverse coupling influence, use a ground that is free of noise
interference as the ground for the capacitors (rough standard values are: R=less than 5kΩ, C=1000
pF to 0.1µF).
• Do not lay analog signal lines close to, in parallel with, or in a crossed arrangement with digital
pulse signal lines or signal lines in which large current changes can occur. Shield both ends of
analog signal lines with noise-free ground.
• Make sure that no digital pulses are applied to or generated from the pins adjacent to the analog
input pin that is being subject to conversion.
3-71
ADC12
• Correct conversion results may not be obtained because of noise interference if the state of port
outputs is changing. To minimize the adverse influences of noise interference, it is necessary to
keep line resistance across the power supply and the VDD pins of the microcontroller at a
minimum. This should be kept in mind when designing an application circuit.
• Adjust the amplitudes of the voltage at the oscillator pin and the I/O voltages at the other pins so
that they fall within the voltage range between VDD and VSS.
10)
To obtain valid conversion data, perform conversion operations several times, discard the maximum
and minimum values of the conversion results, and use an average of the remaining data.
3-72
LC87BK00 Chapter 4
4. Control Functions
4.1
Interrupt Function
4.1.1 Overview
This series of microcontrollers has the capabilities to control three levels of multiple interrupts, i.e., low
level (L), high level (H), and highest level (X). The master interrupt enable register (IE) and interrupt
priority control register (IP) are used to enable or disable interrupts and determine the priority of interrupts.
4.1.2
Functions
1)
Interrupt processing
• Peripheral modules generate an interrupt request to the predetermined vector address when the
interrupt request and interrupt request enable flags are set to 1.
• When the CPU receives an interrupt request from a peripheral module, it determines the level,
priority and interrupt enable status. If the interrupt request is legitimate for processing, the CPU
saves the value of PC in the stack and causes a branch to the predetermined vector address.
• The return from the interrupt routine is accomplished by the RETI instruction, which restores
the old state of PC and the interrupt level.
2)
Multilevel interrupt control
• The interrupt function supports three levels of interrupts, i.e., the low level (L), high level (H),
and highest level (X). The interrupt function will not accept any interrupt requests of the same
level or lower level than the one that is currently being processed.
3)
Interrupt priority
• When interrupt requests to two or more vector addresses occur at the same time, the interrupt
request of the highest level takes precedence over the other interrupt requests. When interrupt
requests of the same level occur at the same time, the one whose vector address is the lowest
has priority.
4)
Interrupt request enable control
• The master interrupt enable register (IE) can be used to control the enabling/disabling of Hand L-level interrupt requests.
• Interrupt requests of the X-level cannot be disabled.
5)
Interrupt disable period
• Interrupts are held disabled for a period of 2 Tcyc after a write operation is performed to the IE
(FE08) or IP (FE09) register, or HOLD mode is released.
• No interrupt can occur during the interval between the execution of an instruction that loads the
PCON (FE07) register and the execution of the next instruction.
• No interrupt can occur during the interval between the execution of a RETI instruction and the
execution of the next instruction.
4-1
Interrupt
6)
Interrupt level control
• Interrupt levels can be selected on a vector address basis.
Table of Interrupts
No.
Vector Address
1
00003H
2
0000BH
3
00013H
4
0001BH
5
00023H
6
0002BH
7
00033H
8
0003BH
9
00043H
10
0004BH
Selectable Level
X or L
X or L
H or L
H or L
H or L
H or L
H or L
H or L
H or L
H or L
Interrupt Sources
INT0
INT1
INT2/T0L/INT4
INT3/base timer
T0H
T1L/T1H
None
SIO1
ADC/T6/T7
Port 0
• Priority level: X  H  L
• When interrupts of the same level occur at the same time, an interrupt with the lowest vector address
is processed first.
7)
It is necessary to manipulate the following special function registers to enable interrupts and to
specify their priority.
• IE, IP
Address
Initial Value
R/W
Name
BIT7
BIT6
BIT5
BIT4
BIT3
BIT2
BIT1
BIT0
FE08
0000 HH00
R/W
IE
IE7
XFLG
HFLG
LFLG
-
-
XCNT1
XCNT0
FE09
0000 0000
R/W
IP
IP4B
IP43
IP3B
IP33
IP2B
IP23
IP1B
IP13
4.1.3
4.1.3.1
1)
2)
3)
4.1.3.2
1)
Circuit Configuration
Master interrupt enable control register (IE) (6-bit register)
This register enables and disables H- and L-level interrupts.
The state of the interrupt level flag can be read.
The register selects the level (L or X) of interrupts to vector addresses 00003H and 0000BH.
Interrupt priority control register (IP) (8-bit register)
This register selects the level (H or L) of interrupts to vector addresses 00013H to 0004BH.
4-2
LC87BK00 Chapter 4
4.1.4
4.1.4.1
1)
Related Registers
Master interrupt enable control register (IE)
This register is a 6-bit register for controlling the interrupts. Bits 6 to 4 are read only.
Address
Initial Value
R/W
Name
BIT7
BIT6
BIT5
BIT4
BIT3
BIT2
BIT1
BIT0
FE08
0000 HH00
R/W
IE
IE7
XFLG
HFLG
LFLG
-
-
XCNT1
XCNT0
IE7 (bit 7): H-/L-level interrupt enable/disable control
A 1 in this bit enables H- and L-level interrupt requests to be accepted.
A 0 in this bit disables H- and L-level interrupt requests to be accepted.
X-level interrupt requests are always enabled regardless of the state of this bit.
XFLG (bit 6): X-level interrupt flag (R/O)
This bit is set when an X-level interrupt is accepted and reset when execution returns from the processing
of the X-level interrupt.
This bit is read only. No instruction can rewrite the value of this bit directly.
HFLG (bit 5): H-level interrupt flag (R/O)
This bit is set when an H-level interrupt is accepted and reset when execution returns from the processing
of the H-level interrupt.
This bit is read only. No instruction can rewrite the value of this bit directly.
LFLG (bit 4): L-level interrupt flag (R/O)
This bit is set when an L-level interrupt is accepted and reset when execution returns from the processing
of the L-level interrupt.
This bit is read only. No instruction can rewrite the value of this bit directly.
(Bits 3, 2): These bits do not exist.
They are always read as 1.
XCNT1 (bit 1): 0000BH interrupt level control flag
A 1 in this bit sets all interrupts to vector address 0000BH to the L-level.
A 0 in this bit sets all interrupts to vector address 0000BH to the X-level.
XCNT0 (bit 0): 00003H interrupt level control flag
A 1 in this bit sets all interrupts to vector address 00003H to the L-level.
A 0 in this bit sets all interrupts to vector address 00003H to the X-level.
4-3
Interrupt
4.1.4.2
1)
Interrupt priority control register (IP)
This register is an 8-bit register that selects the level (H or L) of interrupts to vector addresses
00013H to 0004BH.
Address Initial Value
FE09
0000 0000
R/W
Name
BIT7
BIT6
BIT5
BIT4
BIT3
BIT2
BIT1
BIT0
R/W
IP
IP4B
IP43
IP3B
IP33
IP2B
IIP23
IP1B
IP13
Interrupt
Vector Address
IP Bit
7
0004BH
IP4B
6
00043H
IP43
5
0003BH
IP3B
4
00033H
IP33
3
0002BH
IP2B
2
00023H
IP23
1
0001BH
IP1B
0
00013H
IP13
Value
0
1
0
1
0
1
0
1
0
1
0
1
0
1
0
1
4-4
Interrupt Level
L
H
L
H
L
H
L
H
L
H
L
H
L
H
L
H
LC87BK00 Chapter 4
4.2 System Clock Generator Function
4.2.1
Overview
This series of microcontrollers incorporates five systems of oscillator circuits, i.e., a main clock oscillator,
a subclock oscillator, low- and medium-speed RC oscillators, and a multifrequency RC oscillator as
system clock generator circuits. The low- and medium-speed RC oscillator circuits and multifrequency RC
oscillator circuit have internal resistors and capacitors, so that no external circuit is required.
The system clock can be selected from these five types of clock sources under program control.
4.2.2
Functions
1)
2)
System clock select
• Allows the system clock to be selected under program control from five types of clocks
generated by the main clock oscillator, subclock oscillator, low- and medium-speed RC
oscillators, and multifrequency RC oscillator.
System clock frequency division
• Divides the frequency of the oscillator clock selected as the system clock and supplies the
resultant clock to the system as the system clock.
• The frequency divider circuit has two stages:
1
1
and .
The first stage allows the selection of division ratios of
1
The second stage allows the selection of division ratios of
1
.
and
2
1
1
,
1
2
,
1
4
,
1
, 1
8
16
,
1
32
,
1
64
,
128
3)
4)
5)
Oscillator circuit control
• Allows the start/stop control of the five systems of oscillators to be executed independently
through instructions. The main clock and subclock oscillator circuits share pins (CF1/XT1 and
CF2/XT2) and cannot be used at the same time.
• The CF oscillator circuit may be either a low power dissipation type CF oscillation low
amplifier or a CF oscillation normal amplifier.
Multiplexed input pin function
• The CF oscillator/crystal oscillator pins (CF1/XT1 and CF2/XT2) can also be used as
general-purpose input ports.
Oscillator circuit states and operating modes
Reset
Stopped
Stopped
MediumLow-speed RC
speed RC
Oscillator
Oscillator
(Note1)
Stopped
Running
Reset released
Stopped
Stopped
Stopped
Running
Stopped
Programmable
State established
at entry time
Stopped
State established
at entry time
Programmable
State established
at entry time
Stopped
Running
(Note 2)
Programmable
State established
at entry time
Stopped
Running
(Note 2)
Programmable
State established
at entry time
Stopped
Stopped
Mode/Clock
Main Clock
Normal operation Programmable
HALT
State established
at entry time
HOLD
Stopped
Immediately after State established
exit from HOLD at entry time
mode
X'tal HOLD
Subclock
Stopped
Multifrequency
RC Oscillator
Stopped
State established Stopped
Stopped
Stopped
at entry time
Immediately after State established State established State established State established State established
at entry time
at entry time
at entry time
at entry time
at entry time
exit from X'tal
HOLD mode
System Clock
Medium-speed RC
oscillator
Medium-speed RC
oscillator
Programmable
State established at
entry time
Stopped
Low- or mediumspeed RC oscillator
according to the
state that has been
defined on entry by
bit 1 of SLWRC
register
Stopped
State established at
entry time
See Section 4.3," Standby Function," for the procedures to enter and exit the microcontroller operating
modes.
4-5
System Clock
● Reset
・Main clock stopped.
・Subclock stopped
●リセット RC oscillator
・Low-speed
・メインクロック動作
stopped
・サブクロック停止
・Medium-speed
RC oscillator
・RC
発振動作
started
・周波数可変 RCRC
発振停止
・Multifrequency
oscillator
stopped
● HOLD mode (Note 1)
・All oscillators stopped.
・If the SLWRC register, bit 1 is set to 1:
Since the SLWRC register, bit 0 is
set, and the OCR register, bits 4, 5
are cleared, the low-speed RC
oscillator is activated and designated
as the system clock when HOLD
mode is released.
・If the SLWRC register, bit 1 is set to 0:
Since the OCR register, bits 1, 4, 5
are cleared, the medium-speed RC
oscillator is activated and designated
as the system clock when HOLD
mode is released.
・Since the MRCR register, bits 6, 7
are cleared, the multifrequency RC
oscillator is stopped when HOLD
mode is released.
● X'tal HOLD mode (Note 1)
・The main clock, low- /mediumspeed RC oscillators, and
multifrequency RC oscillator are
stopped. The subclock retains the
state established when X'tal
HOLD mode is entered.
・The contents of OCR, SLWRC,
and MRCR registers remain
unchanged.
・CPU enters this mode after
selecting the subclock, or low-/
medium-speed RC oscillator as
the system clock.
・When X'tal HOLD mode is exited,
the oscillators return to the state
established when the mode is
entered.
● Normal operating mode (Note 1)
・Start/stop of each of the
oscillators programmable
● HALT mode (Note 1)
・All oscillators retain the state
established when HALT mode
is entered.
Note 1: The low-speed RC oscillation is also controlled directly by the watchdog timer. Its oscillation in
the standby mode is also controlled by the watchdog timer. See Section 4.5, "Watchdog Timer,"
for details.
Note 2: After HOLD mode is released, the medium- or low-speed RC oscillator is automatically enabled
and designated as the system clock according to the value of bit 1 of the low-speed RC oscillator
control register (SLWRC) that is established when HOLD mode is entered.
6)
It is necessary to manipulate the following special function registers to control the system clock.
• PCON, OCR, CLKDIV, MRCR, XT2PC, SLWRC
Address
Initial Value
R/W
Name
BIT7
BIT6
BIT5
BIT4
BIT3
BIT2
BIT1
BIT0
FE07
HHHH H000
R/W
PCON
-
-
-
-
-
XTIDLE
PDN
IDLE
FE0C
HHHH H000
R/W
CLKDIV
-
-
-
-
-
CLKDV2 CLKDV1
FE0D
00HH HHHH
R/W
MRCR
-
-
-
-
-
-
FE0E
0000 XX00
R/W
OCR
XT2IN
XT1IN
RCSTOP
CFSTOP
FE43
HHHH 0H00
R/W
XT2PC
-
-
-
-
XTCFSEL
-
XT2DR
XT2DT
FE7C
HHHH H000
R/W
SLWRC
-
-
-
-
-
MRCSEL MRCST
CLKSGL EXTOSC CLKCB5 CLKCB4
4.2.3
Circuit Configuration
4.2.3.1
Main clock oscillator circuit
1)
2)
3)
4)
4.2.3.2
1)
2)
CLKDV0
CFLAMP SLRCSEL SLRCSTAT
The main clock oscillator circuit is prepared for oscillation by connecting a ceramic resonator and a
capacitor to the CF1/XT1 and CF2/XT2 pins and controlling the OCR and XT2PC registers.
The data at the CF1/XT1 and CF2/XT2 pins can be read as bits 2 and 3 of the OCR register.
The CF2/XT2 pin can be used as a general-purpose output (N-channel open drain) port.
Refer to Section 1.7, "Recommended Unused Pin Connections," when 1), 2), or 3) above is not to be
used.
Subclock oscillator circuit
The subclock oscillator is prepared for oscillation by connecting a crystal resonator (32.768 kHz typ),
a capacitor and a damping resistor to the CF1/XT1 and CF2/XT2 pins and controlling the OCR and
XT2PC registers.
The data at the CF2/XT2 pin can be read as bit 3 of the OCR register. The data at the CF1/XT1 pin is
not read as bit 2 of the OCR register.
4-6
LC87BK00 Chapter 4
4.2.3.3
1)
2)
4.2.3.4
1)
2)
4.2.3.5
1)
2)
3)
4.2.3.6
1)
4.2.3.7
1)
2)
3)
4)
4.2.3.8
1)
2)
3)
Internal low-speed RC oscillator circuit
This circuit oscillates due to the internal resistor and capacitor (100 kHz typ).
The internal low-speed RC oscillator serves as the system clock to be used for low-power, low-speed
operation.
Internal medium-speed RC oscillator circuit (conventional RC oscillator circuit)
This circuit oscillates due to the internal resistor and capacitor (1 MHz typ).
The clock from the medium-speed RC oscillator is designated as the system clock after the reset is
released. After HOLD mode is exited, the clock from the medium- or low-speed RC oscillator that is
selected when HOLD mode is entered is designated as the system clock.
Multifrequency RC oscillator circuit (with no variable modulation frequency function)
This circuit oscillates due to the internal resistor and capacitor.
Unlike conventional types (the LC872G00/LC872R00 series), this circuit provides no variable
modulation frequency function; its clock output frequency is fixed at 1/2 of the 16 MHz source
oscillation frequency (8 MHz).
It is suited to generate a main clock which does not require the precision in frequency that the
external CF oscillator would provide.
Power control register (PCON) (3-bit register)
This register specifies the operating mode (normal/HALT/HOLD/X'tal HOLD).
Oscillation control register (OCR) (8-bit register)
This register controls the start/stop operations of the oscillator circuits.
The register selects the system clock.
This register sets the division ratio of the oscillator clock to be used as the system clock to
The data at the CF1/XT1 and CF2/XT2 pins can be read as bits 2 and 3 of this register.
1
1
or
1
2
.
Low-speed RC oscillation control register (SLWRC) (3-bit register)
This register controls the start/stop operation of the low-/medium-speed RC oscillator circuits.
This register switches between the low-speed RC oscillator clock and the medium-speed RC
oscillator clock.
This register selects the amplifier size of the CF oscillator circuit. CF oscillation low amplifier is
effective for reducing power dissipation under such conditions as low voltage, when CF= 4 MHz, or
when the system frequency division ratio = 1/4 to 1/16.
4.2.3.9
CF1/XT1 and CF2/XT2 general-purpose port input control register (XT2PC)
register)
1)
2)
This register controls the functions of the main clock oscillator circuit.
The register controls the general-purpose output (N-channel open drain) of the CF2/XT2 pin.
(3-bit
4.2.3.10 Multifrequency RC oscillation control register (MRCR) (2-bit register)
1)
2)
This register controls the start/stop operation of the multifrequency RC oscillator circuit.
The register selects the main clock from the external CF oscillator and multifrequency RC oscillator.
4.2.3.11 System clock division control register (CLKDIV) (3-bit register)
1)
This register controls the operation of the system clock divider circuit. The division ratios of
1
1
1
1
1
1
, ,
,
,
, and
are available.
4
8
16
32
64
128
4-7
1
1
,
1
2
,
System Clock
CF1/XT1
CF2/XT2
Subclock
Subclock
(X'tal) oscillator
CFSTOP
Main clock
(CF) oscillator
XTCFSEL
CF clock
Multifrequency
RC oscillator
MRCST
Base timer
MRCSEL
Selector
EXTOSC
Main clock
CLKCB5-4
CLKSGL
CLKDV2-0
Frequency
divider (1)
Frequency
divider (2)
Selector
Medium-speed
RC oscillator
RCSTOP
Low-speed RC
oscillator
SLRCSTAT
RC clock
Selector
SLRCSEL
fSCLK: System clock frequency
fCYC: Cycle clock frequency
To watchdog timer &
base timer circuit
Oscillation control from
watchdog timer
System clock
（SCLK）
（minimum instruction cycle）
fCYC = fSCLK÷3
Figure 4.2.1. System Clock Generator Circuit Block Diagram
4.2.4
Related Registers
4.2.4.1
Power control register (PCON) (3-bit register)
1)
This register is a 3-bit register used to specify the operating mode (normal/HALT/HOLD/X'tal
HOLD).
See Section 4.3, "Standby Function," for the procedures to enter and exit the microcontroller
operating modes.
Address
Initial Value
R/W
Name
BIT7
BIT6
BIT5
BIT4
BIT3
BIT2
BIT1
BIT0
FE07
HHHH H000
R/W
PCON
-
-
-
-
-
XTIDLE
PDN
IDLE
(Bits 7 to 3): These bits do not exist.
They are always read as 1.
XTIDLE (bit 2): X'tal HOLD mode setting flag
PDN (bit 1): HOLD mode setting flag
XTIDLE
–
0
1
PDN
0
1
1
Operating Mode
Normal or HALT mode
HOLD mode
X'tal HOLD mode
<1> These bits must be set with an instruction.
• When the CPU enters HOLD mode, all oscillators (main clock, subclock, low-/medium-speed
RC, multifrequency RC) are suspended and the related registers are placed in the states
described below.
If bit 1 of the SLWRC register is set to 1, bit 0 of the SLWRC register is set and bits 4 and 5 of
the OCR register are cleared.
If bit 1 of the SLWRC register is set to 0, bits 1, 4, and 5 of the OCR register are cleared.
4-8
LC87BK00 Chapter 4
• When the CPU returns from HOLD mode, the low- or medium-speed RC oscillator starts
operation depending on the state of the SLWRC and OCR registers and is designated as the
system clock source. The main clock and subclock return to the state that is established before
the CPU enters HOLD mode.
• When the CPU enters X'tal HOLD mode, all oscillators except subclock (main clock,
low-/medium-speed RC, multifrequency RC) are suspended but the state of the OCR register
remains unchanged.
• Since X'tal HOLD mode is used usually for low-current clock counting, less current will be
consumed if the system clock is switched to the subclock and low-/medium-speed RC/
multifrequency RC oscillators are suspended before X'tal HOLD mode is entered.
<2> XTIDLE must be cleared with an instruction.
<3> PDN is cleared when a HOLD mode release signal (INT0, INT1, INT2, INT4, or P0INT) or a reset
signal occurs.
<4> Bit 0 is automatically set when PDN is set.
IDLE (bit 0): HALT mode setting flag
<1> Setting this bit places the CPU into HALT mode.
<2> This bit is automatically set when bit 1 is set.
<3> This bit is cleared on acceptance of an interrupt request or on receipt of a reset signal.
4.2.4.2
1)
Oscillation control register (OCR) (8-bit register)
This register is an 8-bit register that controls the operation of the oscillator circuits, selects the
system clock, and reads data from the CF1/XT1 and CF2/XT2 pins. Except for read-only bits 3 and 2,
all bits of this register can be read or written.
Address
Initial Value
R/W
Name
FE0E
0000 XX00
R/W
OCR
BIT7
BIT6
BIT5
BIT4
CLKSGL EXTOSC CLKCB5 CLKCB4
BIT3
BIT2
XT2IN
XT1IN
BIT1
BIT0
RCSTOP CFSTOP
CLKSGL (bit 7): Clock division ratio select
<1> When this bit is set to 1, the clock selected by bits 4 and 5 is used as the system clock as is.
1
<2> When this bit is set to 0, the clock having a frequency of
of the clock selected by bits 4 and 5 is
2
used as the system clock.
EXTOSC (bit 6): CF1/XT1 and CF2/XT2 function control
<1> When this bit is set to 1 and CFSTOP (bit 0) is set to 1, the CF1/XT1 and CF2/XT2 pins serve as the
pins for subclock oscillation and are prepared for oscillation when a crystal resonator (32.768 kHz
typ), capacitors, and damping resistors are connected. When the OCR register is read in this case, bit
3 reads the data at the CF2/XT2 pin, and bit 2 does not read the data at the CF1/XT1 pin but reads 0.
<2> When this bit is set to 0 and XT2PC (bit 3) is set to 1, the CF1/XT1 and CF2/XT2 pins serve as the
pins for main clock oscillation and are prepared for oscillation when a ceramic resonator, capacitors,
feedback resistors, and damping resistors are connected. Start/stop of the main clock oscillation is
controlled by CFSTOP (bit 0). If the OCR register is read when XT2PC (bit 3) is set to 0, bit 3 reads
the data at the CF2/XT2 pin and bit 2 reads the data at the CF1/XT1 pin.
4-9
System Clock
CLKCB5 (bit 5): System clock select
CLKCB4 (bit 4): System clock select
<1> CLKCB5 and CLKCB4 are used to select the system clock.
<2> CLKCB5 and CLKCB4 are cleared on reset or when HOLD mode is entered.
CLKCB5
0
0
1
1
CLKCB4
0
1
0
1
System Clock
Internal low-/medium-speed RC oscillator
Main clock
Subclock
Main clock
XT2IN (bit 3): CF2/XT2 pin data (read-only)
XT1IN (bit 2): CF1/XT1 pin data (read-only)
<1> Data that can be read via XT1IN varies as shown in the table below according to the value of
EXTOSC (bit 6).
RCSTOP (bit 1): Internal medium-speed RC oscillator circuit control
<1> Setting this bit to 1 stops the oscillation of the internal medium-speed RC oscillator circuit.
<2> Setting this bit to 0 starts the oscillation of the internal medium-speed RC oscillator circuit.
<3> When a reset occurs, this bit is cleared and the internal RC oscillator circuit is enabled for oscillation.
<4> When the CPU enters HOLD mode, this bit is set as described below according to the state of bit 1 of
the SLWRC register.
If bit 1 of the SLWRC register is set to 1, the state of this bit remains unchanged.
If bit 1 of the SLWRC register is set to 0, this bit is cleared and the oscillator starts oscillation and is
designated as the system clock source when the CPU exits HOLD mode.
CFSTOP (bit 0): Main clock oscillator circuit control
<1> Setting this bit to 1 stops the oscillation of the main clock oscillator circuit.
<2> Setting this bit to 0 starts the oscillation of the main clock oscillator circuit.
<3> When a reset occurs, this bit and bit 3 of the XT2PC register are cleared and the CF1/XT1 and
CF2/XT2 pins are configured as input pins.
OCR Register
EXTOSC
CFSTOP
4.2.4.3
1)
XT2PC Register
XTCFSEL
X
0
1
0
1
1
1
1
X
X
0
0
0
1
0
CF1/XT1，
CF2/XT2 State
Main clock
oscillator started
Main clock
oscillator stopped
Subclock oscillator
started
General-purpose
input
General-purpose
input/output
OCR Register (FE0EH)
XT2IN
XT1IN
CF2/XT2
CF1/XT1
pin data
pin data
Undefined
CF2/XT2
pin data
CF2/XT2
pin data
CF2/XT2
pin data
Undefined
0 is read.
CF1/XT1
pin data
CF1/XT1
pin data
Low-speed RC oscillation control register (SLWRC) (3-bit register)
This register is a 3-bit register that controls the operation of the low-/medium-speed RC oscillator
circuits and selects the amplifier size of the CF oscillator circuit.
Address
Initial Value
R/W
Name
BIT7
BIT6
BIT5
BIT4
BIT3
FE7C
HHHH H000
R/W
SLWRC
-
-
-
-
-
4-10
BIT2
BIT1
BIT0
CFLAMP SLRCSEL SLRCSTAT
LC87BK00 Chapter 4
(Bits 7 to 3): These bits do not exist.
They are always read as 1.
CFLAMP (bit 2): CF oscillation amplifier size select control
<1> A 1 in this bit selects the low amplifier size for the CF oscillator circuit.
<2> A 0 in this bit selects the normal amplifier size for the CF oscillator circuit.
* Predefined procedure is required to switch the selection. See Subsection 4.2.5
SLRCSEL (bit 1): Internal low-/medium-speed RC oscillator clock select control
<1> A 1 in this bit selects the clock for the internal low-speed RC oscillator.
<2> A 0 in this bit selects the clock for the internal medium-speed RC oscillator.
SLRCSTAT (bit 0): Internal low-speed RC oscillator circuit control
<1> A 1 in this bit starts the internal low-speed RC oscillator circuit.
<2> A 0 in this bit stops the internal low-speed RC oscillator circuit.
<3> When a reset occurs, this bit is cleared.
<4> This bit is set as described below according to the state of SLRCSEL (bit 1) when the CPU enters
HOLD mode.
If SLRCSEL (bit 1) is set to 1, this bit is set and the oscillator starts oscillation and is designated as
the system clock source when the CPU exits HOLD mode.
If SLRCSEL (bit 1) is set to 0, the state of this bit remains unchanged.
4.2.4.4
CF1/XT1, CF2/XT2 general-purpose port input control register (XT2PC) (3-bit register)
1)
This register is a 3-bit register that controls the general-purpose input at the CF1/XT1 and CF2/XT2
pins.
Address
Initial Value
R/W
Name
BIT7
BIT6
BIT5
BIT4
BIT3
BIT2
BIT1
BIT0
FE43
0000 0000
R/W
XT2PC
-
-
-
-
XTCFSEL
-
XT2DR
XT2DT
(Bits 7 to 4 and 2): These bits do not exist.
They are always read as 1.
XTCFSEL (bit 3): CF1/XT1 and CF2/XT2 input control
<1> This bit and EXTOSC (OCR: FE0EH, bit 6) and CFSTOP (OCR: FE0EH, bit 0) are used to select
the function of the CF1/XT1 and CF2/XT2 pins from among the main clock, subclock, and
general-purpose input port pins. (See 4.2.4.2, "Oscillation control register," for details.)
XT2DR (bit 1): CF2/XT2 input/output control
XT2DT (bit 0): CF2/XT2 output data
CF2/XT2 State
Register Data
XT2DT
XT2DR
Input
Output
０
０
Enabled
Open
１
０
Enabled
Open
０
１
Enabled
Low
１
１
Enabled
Open
Note: To use the CF2/XT2 as a general-purpose output port, set XTCFSEL (XT2PC: FE43H, bit 3) to 0,
CFSTOP (OCR: FE0EH, bit 0) to 1, and EXTOSC (OCR: FE0EH, bit 6) to 0.
4-11
System Clock
4.2.4.5
1)
Multifrequency RC oscillation control register (MRCR) (2-bit register)
This register is a 2-bit register that controls the operation of the multifrequency RC oscillator circuit
and selects the main clock.
Address
Initial Value
R/W
Name
FE0D
00HH HHHH
R/W
MRCR
BIT7
BIT6
MRCSEL MRCST
BIT5
BIT4
BIT3
BIT2
BIT1
BIT0
-
-
-
-
-
-
MRCSEL (bit 7): Multifrequency RC oscillator clock select
<1> When this bit is set to 1, the clock output from the multifrequency RC oscillator is selected as the
main clock. The multifrequency RC oscillator clock will be the system clock if the main clock is
selected as the system clock in the OCR register setting.
<2> When this bit is set to 0, the multifrequency RC oscillator is not selected as the main clock; CF is
designated as the main clock.
<3> This bit is cleared when the CPU enters HOLD mode.
MRCST (bit 6): Multifrequency RC oscillation start control
<1> A 1 in this bit starts the multifrequency RC oscillator circuit.
<2> A 0 in this bit stops the multifrequency RC oscillator circuit.
<3> This bit is cleared when the CPU enters HOLD mode.
(Bits 5 to 0): These bits do not exist.
They are always read as 1.
Note: When the system clock is switched, secure an oscillation stabilization time of 100 μs or longer after the
multifrequency RC oscillator circuit switches from the "oscillation stopped" to "oscillation enabled"
state.
4.2.4.6
1)
System clock division control register (CLKDIV) (3-bit register)
This register controls the frequency division processing of the system clock.
Address
Initial Value
R/W
Name
BIT7
BIT6
BIT5
BIT4
BIT3
FE0C
HHHH H000
R/W
CLKDIV
-
-
-
-
-
BIT2
(Bits 7 to 3): These bits do not exist.
They are always read as 1.
CLKDV2 (bit 2):
CLKDV1 (bit 1):
These bits define the division ratio of the system clock.
CLKDV0 (bit 0):
CLKDV2
CLKDV1
CLKDV0
0
0
0
0
0
1
0
1
0
0
1
1
1
0
0
1
0
1
1
1
0
1
1
1
4-12
Division Ratio
1
1
1
2
1
4
1
8
1
16
1
32
1
64
1
128
BIT1
BIT0
CLKDV2 CLKDV1 CLKDV0
LC87BK00 Chapter 4
4.2.5
Example of Switching the CF Oscillation Amplifier Size
1)
System clock state
Set the system clock to a state other than the CF oscillation (main).
2)
Switch the CF oscillator amplifier size to low amp.
Set CFLAMP (bit 2) of the low-speed RC oscillation control register to 1.
3)
Wait for the CF oscillator stabilization time.
Wait for the CF oscillator stabilization time specified in the latest “Semiconductor Data Sheet.”
4)
Check the CF oscillator (this step is highly recommended especially when using a low-voltage
configuration).
Using the CF oscillation monitoring function, make sure that the system clock is oscillating.
5)
Switch the system clock source.
Set CLKCB4 (bit 4) of the oscillation control register to 1 and CLKCB5 (bit 5) to 0 to switch the
system clock source to CF oscillator (main).
Note: Do not switch the amplifier size of the CF oscillator when the system clock is set to the CF oscillator
(main). Switching the amplifier size in this case may cause unstable oscillation, resulting in a system
malfunction.
Note: The operating voltage range differs for the CF oscillator low and normal amplifiers. Refer to the
latest “Semiconductor Data Sheet” before using the CF oscillator low amplifier.
4-13
Standby
4.3 Standby Function
4.3.1 Overview
This series of microcontrollers supports three standby modes, i.e., HALT, HOLD, and X'tal HOLD modes,
which are used to reduce current consumption at power-failure time or in program standby mode. In
standby mode, the execution of all instructions is suspended.
4.3.2 Functions
1)
HALT mode
• The CPU suspends the execution of instructions but its peripheral circuits continue processing.
(Note 1)
• HALT mode is entered by setting bit 0 of the PCON register.
• Bit 0 of the PCON register is cleared and the CPU returns to normal operating mode when a
reset occurs or an interrupt request is accepted.
2)
HOLD mode
• All oscillations are suspended. The CPU suspends the execution of instructions and the
peripheral circuits stop processing. (Notes 1, 2)
• HOLD mode is entered by setting bit 1 of the PCON register to 1 when bit 2 is set to 0. In this
case, bit 0 of the PCON register (HALT mode setting flag) is automatically set.
• When a reset occurs or a HOLD mode release signal (INT0, INT1, INT2, INT4, or port 0
interrupt) occurs, bit 1 of the PCON register is cleared and the CPU switches to HALT mode.
3)
X'tal HOLD mode
• All oscillations except the subclock oscillation are suspended. The CPU suspends the execution
of instructions and all the peripheral circuits except the base timer stop processing. (Notes 1, 2)
• X'tal HOLD mode is entered by setting bit 1 of the PCON register to 1 when bit 2 is set to 1. In
this case, bit 0 of the PCON register (HALT mode setting flag) is automatically set.
• When a reset occurs or a X’tal HOLD mode release signal (base timer interrupt, INT0, INT1,
INT2, INT4, or port 0 interrupt) occurs, bit 1 of the PCON register is cleared and the CPU
switches to HALT mode.
Note 1: The low-speed RC oscillation is also controlled directly by the watchdog timer. Its oscillation in
the standby mode is also controlled by the watchdog timer. See Section 4.5, "Watchdog Timer,”
for details.
Note 2: Do not allow the CPU to enter HOLD, or X'tal HOLD mode while AD conversion is in progress.
Make sure that ADSTART(ADCRC register, bit 2) is set to 0 before placing the CPU into one of
the standby modes.
4-14
LC87BK00 Chapter 4
4.3.3 Related Register
4.3.3.1
1)
Power control register (PCON) (3-bit register)
This register is a 3-bit register that specifies the operating mode (normal/HALT/HOLD/X'tal HOLD).
Address Initial Value
FE07
HHHH H000
R/W
Name
BIT7
BIT6
BIT5
BIT4
BIT3
BIT2
BIT1
BIT0
R/W
PCON
-
-
-
-
-
XTIDLE
PDN
IDLE
(Bits 7 to 3): These bits do not exist.
They are always read as 1.
XTIDLE (bit 2): X'tal HOLD mode setting flag
PDN (bit 1): HOLD mode setting flag
XTIDLE
－
0
1
PDN
0
1
1
Operating mode
Normal or HALT mode
HOLD mode
X'tal HOLD mode
<1> These bits must be set with an instruction.
• When the CPU enters HOLD mode, all oscillators (main clock, subclock, low-/medium-speed
RC, multifrequency RC) are suspended and the related registers are placed in the states
described below:
If bit 1 of the SLWRC register is set to 1, bit 0 of the SLWRC register is set, and bits 4 and 5
of the OCR register are cleared.
If bit 1 of the SLWRC register is set to 0, bits 1, 4, and 5 of the OCR register are cleared.
• When the CPU returns from HOLD mode, low- or medium-speed RC oscillator starts
oscillation according to the values of the SLWRC and OCR registers and is designated as the
system clock source. The main clock and subclock return to the state that is established before
the CPU enters HOLD mode and the multifrequency RC oscillator stops oscillation.
• When the CPU enters X'tal HOLD mode, all oscillators except subclock (main clock,
low-/medium-speed RC, multifrequency RC) are suspended, but the contents of the OCR,
SLWRC, and MRCR registers remain unchanged.
• Since no adequate oscillation stabilization time can be secured for the main clock and
multifrequency RC oscillator when the CPU returns from X'tal HOLD mode, it is necessary to
select the subclock or low-/medium-speed RC oscillator as the system clock to be used when
X'tal HOLD mode is entered.
• Since X'tal HOLD mode is usually used for low-current clock counting, less current will be
consumed if the system clock is switched to the subclock, and low-/medium-speed RC/
multifrequency RC oscillators are suspended before X'tal HOLD mode is entered.
<2> XTIDLE must be cleared with an instruction.
<3> PDN is cleared when a HOLD mode release signal (INT0, INT1, INT2, INT4, or port 0 interrupt) or a
reset signal occurs.
<4> Bit 0 is automatically set when PDN is set.
IDLE (bit 0): HALT mode setting flag
<1> Setting this bit places the CPU into HALT mode.
<2> This bit is automatically set when bit 1 is set.
<3> This bit is cleared on acceptance of an interrupt request or on receipt of a reset signal.
4-15
Standby
Note 1: The low-speed RC oscillation is also controlled directly by the watchdog timer. Its oscillation in
the standby mode is also controlled by the watchdog timer. See Section 4.5, "Watchdog Timer" for
details.
4-16
LC87BK00 Chapter 4
Table 4.3.1. Standby Mode Operations
Item/Mode
Reset State
HALT Mode
HOLD Mode
X'tal HOLD Mode
• RES applied
• Reset from LVD
• Reset from watchdog
timer
Initialized as shown in
separate table
(When watchdog timer
reset: WDTCNT
register, bit 7 is set)
PCON register
Bit 1=0
Bit 0=1
PCON register
Bit 2=0
Bit 1=1
WDTCNT, bit 5 is
cleared if WDTCNT
register, bit 4=0 and bit
3=1.
• WDTCNT register, bit 5 • WDTCNT register,
Stopped
State established at
entry time
Internal low-speed Stopped
RC oscillation
State established at
entry time (Note 1)
Stopped
Running
Internal
medium-speed RC
oscillation
State established at
entry time
Stopped
Stopped
Subclock
oscillation
Stopped
State established at
entry time
Stopped
State established at entry
time
Multifrequency
RC oscillation
CPU
I/O pin state
RAM
Stopped
State established at
entry time
Stopped
←
Data retained
Stopped
Stopped
Stopped
←
Data retained
Stopped
←
Data retained
Stopped
State established at entry
time
Stopped
Entry conditions
Data changed on
entry
Main clock
oscillation
Initialized
See Table 4.3.2.
• RES: Undefined
• LVD: Undefined or
data retained (depends
on supply voltage)
• When watchdog timer
reset: Data retained
Base timer
Stopped
State established at
entry time
Peripheral modules Stopped
State established at
except base timer
entry time (Note 2)
• Interrupt request
Exit conditions
Entry conditions
accepted.
cancelled.
• Reset/entry conditions
established
Returned mode
Data changed on
exit
Normal mode
None
PCON register
Bit 2=1
Bit 1=1
is cleared if WDTCNT
bit 5 is cleared if
register, bit 4=0 and bit
WDTCNT register,
3=1.
bit 4=0 and bit 3=1.
• PCON, bit 0 turns to 1.
• PCON, bit 0 turns to 1.
• If SLWRC register
(FE7C), bit 1 is reset,
OCR register (FE0E),
bits 5, 4, and 1 are
cleared.
• If SLWRC register
(FE7C), bit 1 is set,
SLWRC register (FE7C),
bit 0 is set and OCR
register (FE0E), bits 5
and 4 are cleared.
Stopped
Stopped
(Note 1)
Stopped
• Interrupt request from
INT0 to INT2, INT4, or
port 0
• Reset/entry conditions
established
Normal mode (Note 2) HALT mode (Note 2)
PCON register, bit 0 = 0 PCON register, bit 1=0
Stopped (Note 1)
• Interrupt request from
INT0 to INT2, INT4,
port 0, or base timer
• Reset/entry conditions
established
HALT mode (Note 2)
PCON register, bit 1=0
Note 1: The low-speed RC oscillation is also controlled directly by the watchdog timer. Its oscillation in the
standby mode is also controlled by the watchdog timer. See Section 4.5, "Watchdog Timer" for details.
Note 2: The CPU switches to the reset state if it exits the current mode on the establishment of reset/entry
conditions.
4-17
Standby
Table 4.3.2. Pin States and Operating Modes (This series)
Pin
Name
Reset Time
• Input pin
RES
CF1/XT1 • Pull-down output
• Oscillation not
started
After reset release:
• Input pin
• Oscillation not
started
Normal Mode
HALT Mode


• CF oscillation inverter 
input/general-purpose
input selected by bit 3 of
register XT2PC(FE43H)
• Oscillation enable or
disable controlled by
register OCR (FE0EH)
• Feedback resistors • Feedback resistor
between CF1 and CF2
for CF and XT are
turned off.
controlled by a program
CF2/XT2 • High-impedance
• Oscillation not
started
After reset release:
• Input pin
• Oscillation not
started
• CF oscillation inverter 
input/general-purpose
input selected by bit 3 of
register XT2PC(FE43H)
• Oscillation enable or
disable controlled by
register OCR (FE0EH).
• Feedback resistors • Feedback resistor
for CF and XT are
between CF1 and CF2
turned off.
controlled by a
program
P00-P07
P10-P17
P20-P21
P70
• Input mode
• Input/output/pull-up
• Pull-up resistor off resistor controlled by a
program
• Input mode
• Input/output/pull-up
• Pull-up resistor off resistor controlled by a
program
• Input mode
• Input/output/pull-up
• Pull-up resistor off resistor controlled by a
program
• Input mode
• Input/output/pull-up
• Pull-up resistor off resistor controlled by a
program
HOLD Mode
On Exit from
HOLD Mode

• CF oscillation inverter
input/general-purpose
input is in the state
established on entry
into HOLD mode.

• State established
on entry into
HOLD mode
• Feedback resistor
between CF1 and CF2
is in the state
established on entry
into HOLD mode.
• CF oscillation inverter • State established
output/general-purpose on entry into
input/output is in the
HOLD mode
state established on
entry into HOLD
mode.

• Feedback resistor
between CF1 and CF2
is in the state
established on entry
into HOLD mode.








• Input mode

• Pull-up resistor
off
4-18
• Same as in
normal mode
LC87BK00 Chapter 4
●Reset
state entry conditions
• Low level applied to RES pin
• Reset signal generated by internal
reset function (POR/LVD)
• Reset signal generated by watchdog
timer
●HOLD
mode entry condition
• PCON register (FE07H), bit 2 set to
0 and bit 1 to 1
●All
modes
●Reset
• Main clock stopped
• Subclock stopped
• Low-speed RC oscillator
stopped
• Medium-speed RC oscillator
started
• Multifrequency RC oscillator
stopped.
• All registers initialized
●HOLD
mode (Note 3)
• All oscillators stopped
• If SLWRC register, bit 1 is set to 1:
Since the SLWRC register, bit 0 is
set, and the OCR register, bits 4, 5
are cleared, the low-speed RC
oscillator is activated and
designated as the system clock
when HOLD mode is released.
• If the SLWRC register, bit 1 is set
to 0:
Since the OCR register, bits 1, 4, 5
are cleared, the medium-speed RC
oscillator is activated and
designated as the system clock.
when HOLD mode is released.
• Since the MRCR register, bits 6, 7
are cleared, the multifrequency RC
oscillator is stopped when HOLD
mode is released.
• CPU and peripheral modules are
stopped.
operating mode
• Start/stop of oscillators
programmable
• CPU and peripheral modules run
normally.
●HALT
mode
• All oscillators retain the state
established when HALT mode is
entered.
• CPU stopped. Peripheral
modules keep running.
mode release conditions
• INT0 or INT1 level interrupt request
generated
• Request for INT2, INT4, or port 0
interrupt generated
• Reset/entry conditions established
(Note 1)
●X’tal
HOLD mode entry conditions
• PCON register (FE07H), bit 2 set to
1 and bit 1 to 1
●X’tal
HOLD mode (Note 3)
• The main clock, low-/mediumspeed RC and multifrequency RC
oscillators stopped. The subclock
retains the state established when
X'tal HOLD mode is entered.
• The contents of OCR, SLWRC, and
MRCR registers remain unchanged
• CPU enters this mode after
selecting subclock or low-/mediumspeed RC oscillator as the system
clock.
• CPU and all peripheral modules
except the base timer stop
operation and the base timer retains
the state established when X'tal
HOLD mode is entered.
• When X'tal HOLD mode is exited,
the oscillators return to the state
established when the mode is
entered
●X'tal
●HALT
mode entry condition
• PCON register (FE07H), bit 1 set to
0 and bit 0 to 1
state release conditions
• Lapse of predetermined time after
the reset/entry conditions are
removed.
●Normal
●HOLD
●HALT
●Reset
mode release conditions
• Interrupt request accepted (Note 2)
• Reset/entry conditions established
(Note 1)
HOLD mode release conditions
• Base timer interrupt request
generated.
• INT0 or INT1 level interrupt request
generated.
• Request for INT2, INT4, or port 0
interrupt generated
• Reset/entry conditions established
(Note 1)
Note 1: The CPU enters the reset state when the reset/entry conditions are established.
Note 2: The CPU cannot return from HALT mode since no interrupt request can be accepted unless its interrupt level is higher
than the interrupt level that placed the CPU into HALT, HOLD, or X'tal HOLD mode.
Note 3: The low-speed RC oscillation is also controlled directly by the watchdog timer. Its oscillation in the standby
mode is also controlled by the watchdog timer. See Section 4.5, "Watchdog Timer," for details.
Interrupt level at which the CPU entered
HALT, HOLD, or X'tal HOLD mode
Interrupt request level that can release
HALT mode
No interrupt request present
X, H and L levels
L level
X and H levels
H level
X level
X level
None (unable to release with interrupt)
Figure. 4.3.1 Standby Mode State Transition Diagram
4-19
Reset
4.4 Reset Function
4.4.1 Overview
The reset function initializes the microcontroller when it is powered on or while it is running.
4.4.2 Functions
This series of microcontrollers provides the following three types of reset functions:
1)
2)
3)
External reset via the RES pin
The microcontroller is reset without fail by applying and holding a low level to the RES pin for 200
μs or longer. Note, however, that a low level of a small duration (less than 200 μs) is likely to trigger
a reset.
The RES pin can serve as a power-on reset pin when it is provided with an appropriate external time
constant.
Internal reset
The internal reset function is available in two types: the power-on reset (POR) that triggers a reset
when power is turned on and the low-voltage detection reset (LVD) that triggers a reset when the
power voltage falls below a certain level. Options are available to set the power-on reset resetting
level, to enable (use) and disable (non-use) the low-voltage detection reset function, and to set the
threshold level.
Reset function using a watchdog timer
The watchdog timer of this series of microcontroller can be used to generate a reset, by the internal
low-speed RC oscillator or the subclock, at a predetermined time interval.
An example of a reset circuit is shown in Figure 4.4.1. The external circuit connected to the reset pin
shows an example that the internal reset function is disabled and an external power-on reset circuit is
configured.
Exterior of
microcontroller
Interior of
microcontroller
Watchdog
timer (WDT)
RES
Sync. circuit
Internal reset
circuit
(POR/LVD)
Figure 4.4.1.
Sample Reset Circuit Block Diagram
4-20
Internal
reset signal
LC87BK00 Chapter 4
4.4.3 Reset State
When a reset is generated by the RES pin, internal reset circuit, or watchdog timer, the hardware
functional blocks of the microcontroller are initialized by the reset signal that is in synchronization with
the system clock.
Since the system clock is switched to the internal medium-speed RC oscillator when a reset occurs,
hardware initialization is also carried out immediately even at power-on time. The system clock must be
switched to the main clock when oscillation of the main clock is stabilized.
On reset, the program counter is initialized to the program start address selected by the user option. The
special function registers (SFRs) are also initialized to the values that are listed in the Special Function
Register (SFR) Map shown in Appendix A-I.
<Notes and precautions>
• The stack pointer is initialized to 0000H.
• Data RAM is never initialized by a reset. Consequently, the contents of RAM are undefined at
power-on time.
• When using the internal reset function, it is necessary to implement and connect an external circuit
to the reset pin according to the user's operating environment. Be sure to review and observe the
operating specifications, circuit configuration, precautions, and considerations discussed in Section
4.6, "Internal Reset Function."
4-21
WDT
4.5
Watchdog Timer (WDT)
4.5.1
Overview
This series of microcontrollers incorporates a watchdog timer (WDT) that has the following features:
1)
Capable of generating an internal reset signal on an overflow occurring in a timer that runs on either
an internal low-speed RC oscillator clock or subclock.
2)
Operation when the CPU enters standby mode can be selected from three modes (continue count
operation, stop operation, and stop count operation while retaining the count value).
* The primary function of the watchdog timer is to detect program runaway conditions. The use of the
watchdog timer is highly recommended to enhance system reliability.
4.5.2
Functions
1)
Watchdog timer function
• A 17-bit up-counter (WDTCT) runs on the WDT clock (selected from either the internal
low-speed RC oscillator clock or subclock). A WDT reset (internal reset) signal is generated
when the overflow time (selected out of 8 time values) that is selected by the watchdog timer
control register (WDTCNT) expires. At this time, the WDT reset detection flag (WDTRSTF) is
set. Since the WDTCT can be cleared by a program, it is necessary to code the program so that
the WDTCT can be cleared at regular intervals.
• If the WDT operation is started with the internal low-speed RC oscillator clock selected as the
WDT clock source, the internal low-speed RC oscillator circuit is controlled by both the
low-speed RC oscillation control register (SLWRC) and the WDT. Since they control the
oscillation independently of each other, even if the system clock happens to be suspended by a
program runaway condition, the WDT continues operation, making it possible to detect the
runaway condition.
• If the WDT operation is started when the subclock is selected as the WDT clock, a WDT reset
is generated on detection of a subclock oscillation suspended by the XT1 and XT2 function
control bit (EXTOSC) of the oscillation control register (OCR) or on entry into HOLD mode.
In this case, WDTRSTF is set.
2)
Standby mode time operations
• The action that the WDT takes in standby mode can be selected from three operating modes:
“continue count operation,” “stop operation,” and “stop count operation while retaining the
count value.” If the internal low-speed RC oscillator clock is selected as the WDT clock source
when “continue count operation” is selected, an operating current of several dozen A is
always flowing in the IC even when it is in standby mode because the internal low-speed RC
oscillator circuit is continuing oscillation. (For details, refer to the latest "Semiconductor Data
Sheet.")
3)
It is necessary to manipulate the following special function register to control the watchdog timer
(WDT).
• WDTCNT
Address
Initial Value
R/W
FE79
0000 0000
R/W WDTCNT WDTRSTF WDTCKSL WDTRUN IDLOP1
Name
BIT7
BIT6
BIT5
4-22
BIT4
BIT3
IDLOP0
BIT2
BIT1
BIT0
WDTSL2 WDTSL1 WDTSL0
LC87BK00 Chapter 4
4.5.3
Circuit Configuration
4.5.3.1
WDT control register (WDTCNT) (8-bit register)
1)
This register is used to manipulate the WDT reset detection flag, to select operation in standby mode,
to select the overflow time, and to control the operation of the WDT.
Note: The WDTCNT is initialized to 00H when a low-level signal is applied to the external RES pin or a
reset is triggered by the internal reset (POR/LVD) function. Bit 6 and bits 4 to 0 of the WDTCNT
are not initialized, however, when a WDT-triggered reset occurs.
Note: The WDTCNT is disabled for writes once WDT operation is started (WDTRUN set to 1). If the
instruction "MOV #55H, WDTCNT" is executed in this case, the WDTCT is cleared and count
operation is restarted at a count value of 0 (the WDTCT is not cleared when it is loaded with 55H
by any other instruction).
Note: The internal low-speed RC oscillator circuit is started by setting WDTCKSL (WDTCNT, bit 6) to 0
and WDTRUN (WDTCNT, bit 5) to 1. Once the oscillator starts oscillation, operating current of
several dozen μA flows. (For details, refer to the latest "Semiconductor Data Sheet.")
Note that the oscillation is also started by setting SLRCSTAT (SLWRC, bit 0) to 1.
4.5.3.2
1)
WDT counter (WDTCT) (17-bit counter)
Operation start/stop:
Start/stop is controlled by the 1/0 value of WDTRUN. The CPU enters standby
mode when WDTRUN is set to 1 and IDLOP1 and IDLOP0 (WDTCNT, bits 4
and 3) are set to 2.
2) Count clock:
The WDT clock (selected from the internal low-speed RC oscillator clock or
subclock).
3) Overflow:
Generated when the WDTCT count value matches the count value selected by
WDTSL2 to WDTSL0 (WDTCNT, bits 2 to 0).
* Generates the WDT reset signal, the WDTRUN clear signal, and the
WDTRSTF (WDTCNT, bit 7) set signal.
4) Reset:
Setting WDTRUN to 0, or setting WDTRUN to 1 and executing the “MOV
#55H, WDTCNT” instruction.
* See Figure 4.5.2 for details on WDT operation.
4-23
WDT
ＳLＲＣＳＴＡＴ
（SLWRC ｂｉｔ０）
ＰＤＮ
（ＰＣＯＮ ｂｉｔ１）
ＸＴＩＤＬＥ
（ＰＣＯＮ ｂｉｔ２）
Low-speed
RC oscillation
control circuit
Enable
oscillation
ＷＤＴＲＵＮ
To system clock
ＷＤＴＣＫＳＬ
Oscillation
control
WDT
low-speed
RC oscillation
control circuit
Oscillation stopped
Internal
low-speed RC
oscillator circuit
BUS
Write WDTCNT
MOV #55H,WDTCNT
write instruction
detector circuit
ＸＴＣＬＫ
Selector
Low-speed RC oscillator clock
Clock
WDT counter
（ＷＤＴＣＴ）
Reset
ＷＤＴＲＵＮ
Clock stopped
Selector
ＷＤＴＣＫＳＬ
Set
WDT reset
generator
circuit
ＷＤＴＲＳＴ＝１
WDTRUN clear signal
WDT reset
WDTRSTF set signal
３
ＷＤＴＳＬ２-０
ＩＤＬＯＰ１-０＝２
Standby mode
ＷＤＴＲＳＴ＝０
ＩＤＬＯＰ１-０＝１
Enter standby mode
WDTRUN clear signal
ＷＤＴＲＵＮ
ＷＤＴＣＫＳＬ
WDTRUN clear signal
WDT reset
WDTRSTF set signal
ＥＸＴＯＳＣ
（ＯＣＲ ｂｉｔ６）
Enter HOLD mode
Figure 4.5.1.
Watchdog Timer Block Diagram
4-24
LC87BK00 Chapter 4
Overflow
*Operation performed when IDLOP1-0 are set to 0 or 3 (continue count operation)
WDTSL2-0 set count value
WDTCT
Count value 0
Time set in WDTSL2-0
"MOV #55H,WDTCNT"
instruction executed
(WDTCT cleared to 0)
WDT operation started
(WDTRUN=1)
Low-speed RC oscillator
started (Note)
WDT reset signal generated
WDTRUN cleared to 0
WDTRSTF set to 1
Low-speed RC oscillator stopped
(Note)
*Operation performed when IDLOP1-0 are set to 1 (stop operation)
Standby mode entered
WDTSL2-0 set count value
WDTCT
Count value 0
WDT operation started
(WDTRUN=1)
Low-speed RC
oscillator started (Note)
WDTRUN cleared to 0
Low-speed RC
oscillator stopped
(Note)
*Operation performed when IDLOP1-0 are set to 2 (stop count operation while retaining the count value)
Standby mode entered
Low-speed RC oscillator
stopped (Note)
Standby mode exited
Low-speed RC oscillator
started (Note)
Overflow
WDTSL2-0 set count value
WDTCT
Count value 0
Time set in WDTSL2-0 + Standby mode time
WDT operation started
(WDTRUN=1)
Low-speed RC
oscillator started (Note)
WDT reset signal generated
WDTRUN cleared to 0
WDTRSTF set to 1
Low-speed RC oscillator stopped
(Note)
Note: Oscillation start/stop control for low-speed RC oscillator circuit is performed when WDTCKSL is set to 0.
Figure 4.5.2.
Sample Watchdog Timer Operation Waveforms
4.5.4
Related Register
4.5.4.1
WDT control register (WDTCNT)
1)
This register is used to manipulate the WDT reset detection flag, to select the standby mode
operation, to select the overflow time, and to control the operation of the WDT.
Address
Initial Value
R/W
Name
BIT7
BIT6
BIT5
FE79
0000 0000
R/W WDTCNT WDTRSTF WDTCKSL WDTRUN
BIT4
BIT3
BIT2
BIT1
BIT0
IDLOP1
IDLOP0
WDTSL2
WDTSL1
WDTSL0
WDTRSTF (bit 7): WDT reset detection flag
This bit is cleared when a reset is triggered by applying a low level signal to the external RES pin or by
using the internal reset (POR/LVD) function.
This bit is set when a WDT-triggered reset occurs.
This flag can be rewritten with an instruction.
WDTCKSL (bit 6): WDTCT input clock select
WDTCKSL
0
1
WDTCT Input Clock
Internal low-speed RC oscillator
Subclock
4-25
WDT
WDTRUN (bit 5): WDT operation control
Setting this bit to 0 stops the WDT operation.
Setting this bit to 1 starts the WDT operation.
IDLOP1 (bit 4):
IDLOP0 (bit 3):
IDLOP1
0
0
1
1
Standby mode operation select
IDLOP0
0
1
0
1
Standby Mode Operation
Continue count operation
Stop operation
Stop count operation while retaining the count value
Continue count operation
* See Figure 4.5.2 for details of the WDT operating modes.
WDTSL2 (bit 2):
WDTSL1 (bit 1):
Overflow time select
WDTSL0 (bit 0):
WDTSL2
0
0
0
0
1
1
1
1
WDTSL1
0
0
1
1
0
0
1
1
WDTSL0
0
1
0
1
0
1
0
1
WDTCT Set Count Value and Overflow
Generation Time Example
Count
Value
1024
2048
4096
8192
16384
32768
65536
131072
Low-speed RC
Clock
10.24ms
20.48ms
40.96ms
81.92ms
163.8ms
327.6ms
655.3ms
1.310s
Subclock
31.25ms
62.50ms
125.0ms
250.0ms
500.0ms
1.000s
2.000s
4.000s
* Time values in the low-speed RC clock column of the table refer to the time for a WDTCT overflow to
occur when the low-speed RC oscillation frequency is 100 kHz (typ). The low-speed RC oscillation
frequency varies from IC to IC. For details, refer to the latest "Semiconductor Data Sheet."
* Time values in the subclock column of the table refer to the time for a WDTCT overflow to occur when
the 32.768 kHz X’tal oscillator is used.
Note: The WDTCNT is initialized to 00H when a low-level signal is applied to the external RES pin or a
reset is triggered by the internal reset (POR/LVD) function. Bit 6 and bits 4 to 0 of the WDTCNT are
not initialized, however, when a WDT-triggered reset occurs.
Note: The WDTCNT is disabled for writes once the WDT operation is started (WDTRUN set to 1). If the
instruction "MOV #55H, WDTCNT" is executed in this case, the WDTCT is cleared and count
operation is restarted at a count value of 0 (the WDTCT is not cleared when it is loaded with 55H by
any other instruction).
Note: The internal low-speed RC oscillator circuit is started by setting WDTCKSL to 0 and WDTRUN to 1.
Once the oscillator starts oscillation, operating current of several dozen μA flows. (For details, refer
to the latest "Semiconductor Data Sheet.") Note that the oscillation is also started by setting
SLRCSTAT (SLWRC, bit 0) to 1.
4-26
LC87BK00 Chapter 4
4.5.5
Using the Watchdog Timer
Code a program so that instructions for clearing the watchdog timer periodically are executed.
1) Starting the watchdog timer
(1) Set the time for a WDT reset to occur to WDTCKSL (WDTCNT, bit 6) and WDTSL2 to
WDTSL0 (WDTCNT, bits 2 to 0).
(2) Set the WDT standby mode operation (HALT/HOLD/X’tal HOLD) to IDLOP1 to IDLOP0
(WDTCNT, bits 4 to 3).
(3) After (1) and (2), set WDTRUN (WDTCNT, bit 5) to 1.
The watchdog timer starts functioning when WDTRUN is set to 1. Once the watchdog timer
starts operation, WDTCNT is disabled for writes; it is only possible to clear WDTCT and read
WDTCNT. Consequently, the watchdog timer can never be stopped with an instruction. The
function of the watchdog timer is stopped only when a low level signal is applied to the external
RES pin, a reset by the internal reset (POR/LVD) function occurs, or standby mode is entered
when IDLOP1 to IDLOP0 are set to 1. In this case, WDTRUN is cleared.
2)
Clearing the WDTCT
When the watchdog timer starts operation, WDTCT counts up. When this WDTCT overflows, a
WDT reset occurs. To run the program in normal mode, it is necessary to periodically clear WDTCT
before it overflows. Execute the following instruction to clear WDTCT while it is running:
MOV #55H, WDTCNT
3)
Detecting a runaway condition
Unless the above-mentioned instruction is executed at regular intervals, WDTCT overflows because
the watchdog timer is not cleared. If an overflow occurs, the watchdog timer considers that a
program runaway has occurred and triggers a WDT reset. In this case, WDTRSTF (WDTCNT, bit
7) is set. After a WDT reset occurs, the program execution restarts at address 0000H. (In the flash
ROM version, the program execution restarts at the address selected as an option.)
4-27
WDT
4.5.6
Notes on the Use of the Watchdog Timer
1)
When the internal low-speed RC oscillator clock is selected as the WDT clock (WDTCKSL = 0)
• If the internal low-speed RC oscillator clock is not to be used as the system clock, set
SLRCSTAT (SLWRC, bit 0) to 0 (the start/stop of the internal low-speed RC oscillator circuit
is also controlled from the watchdog timer side). If SLRCSTAT (SLWRC, bit 0) is set to 1, the
internal low-speed RC oscillator circuit continues oscillation in HALT mode even though the
watchdog timer is running with IDLOP1 and IDLOP0 set to 1 or 2.
• To realize ultra-low-power operation using HOLD mode, it is necessary to disable the watchdog
timer from running in HOLD mode by setting IDLOP1 and IDLOP0 to 1 or 2. When setting
IDLOP1 and IDLOP0 to 0 or 3, several dozen μA of operating current flows at all times
because the low-speed RC oscillator circuit continues oscillating even in HOLD mode.
• If standby mode is entered when the watchdog timer is running with IDLOP1 and IDLOP0 set
to 2, the internal low-speed RC oscillator circuit stops oscillation and the watchdog timer stops
count operation and retains the count value. When the CPU subsequently exits standby mode,
the low-speed RC oscillator circuit resumes oscillation and the watchdog timer restarts count
operation. If the period from the release of standby mode to the next entry into standby mode is
less than “low-speed RC oscillator clock  4,” however, the low-speed RC oscillator circuit
may not stop oscillation when the CPU enters standby mode. In such a case (standby mode is
on), several dozen μA of operating current flows because the low-speed RC oscillator circuit is
active though the watchdog timer is inactive.
To minimize the standby power requirement of the set, code the program so that an interval of
low-speed RC oscillator clock  4 or longer is provided from the release of standby mode to the
next entry into standby mode (The low-speed RC oscillation frequency varies from IC to IC.
Refer to the latest "Semiconductor Data Sheet" for details.
2)
When the subclock is selected as the WDT clock (WDTCKSL = 1)
• When the watchdog timer is used with WDTCKSL set to 1, set EXTOSC (OCR, bit 6) to 1 and
start the watchdog timer operation with a program control allowing the subclock oscillator to be
stabilized.
• If the CPU detects that the subclock oscillation has stopped when EXTOSC (OCR, bit 6) is set
to 0 or when HOLD mode is entered while the watchdog timer is running, the watchdog timer
considers that a program runaway has occurred and triggers a WDT reset. In this case
WDTRSTF is set.
* This mode is primarily used for applications using the real-time clock to realize low-power
operation.
4-28
LC87BK00 Chapter 4
4.6
Internal Reset Function
4.6.1
Overview
This series of microcontrollers incorporates internal reset functions called the power-on reset (POR) and
low voltage detection reset (LVD). The use of these functions contribute to a reduction in the number of
externally required reset circuit components (reset IC, etc.).
4.6.2
Functions
1)
Power-on reset (POR) function
POR is a hardware feature that generates a reset to the microcontroller when the power is turned on.
This function allows the user to select the POR release level by option only when the low voltage
detection reset function is set to “disable.” It is necessary to use the below mentioned low voltage
detection reset function together with this function, or configure an external reset circuit if chatter
occurs when power is turned on or if there is a possibility that a momentary power loss may occur.
2)
Low voltage detection reset (LVD) function
This function, when used together with the POR function, can generate a reset when power is turned
on and when the power level lowers. As a user option, the use (enable) or non-use (disable) and the
detection level of this function can be specified.
4.6.3
Circuit Configuration
The internal reset circuit consists of the POR, LVD, pulse stretcher circuit, capacitor CRES discharging
transistor, external capacitor CRES + pull-up resistor RRES, or pull-up resistor RRES alone. The circuit
diagram of the internal reset circuit is provided in Figure 4.6.1.
• Pulse stretcher circuit
The pulse stretcher circuit stretches the POR and LVD reset signals. It is used to stretch the internal
reset period and discharge the external capacitor CRES connected to the reset pin. The stretching time
lasts from 30 s to 100 s.
• Capacitor CRES discharging transistor
This is an N-channel transistor used to discharge the external capacitor CRES connected to the reset
pin. If the capacitor CRES is not to be connected to the reset pin, it is possible to monitor the internal
reset signal by connecting only the external pull-up resistor RRES.
• Option selector circuit
The option selector circuit is used to configure the LVD options. This circuit selects whether to
enable or disable the LVD and selects its detection level. See Subsection 4.6.4.
• External capacitor CRES + Pull-up resistor RRES
After the reset signal from the internal reset circuit is released, the reset period is further stretched
according to the external CR time constant. This enables the microcontroller to avoid repetitive
entries and releases of the reset state from occurring when power-on chatter occurs. The circuit
configuration shown in Figure 4.6.1, in which the capacitor CRES and pull-up resistor RRES are
externally connected, is recommended when both POR and LVD functions are to be used. The
recommended constant values are: CRES = 0.022 F and RRES = 510 kΩ. The external pull-up resistor
RRES must always be installed even when the set's specifications inhibit the installation of the external
capacitor CRES to the reset pin.
4-29
Internal Reset
Interior of microcontroller
RRES =510kΩ
RES
Reset
CRES =0.022μF
Power-on reset
（POR）
Pulse stretcher
Option
Figure 4.6.1.
4.6.4
Low voltage
detection reset
(LVD)
Internal Reset Circuit Configuration
Options
The POR and LVD options are available for the reset circuit.
1) LVD Reset Function Options
Enable: Use
Disable: Non-use
2) LVD Reset Level Option
3) POR Release Level Option
Typical Value of
Selected Option
Min. Operating
VDD Value (*)
Typical Value of
Selected Option
Min. Operating
VDD Value (*)
–
"2.81V"
"3.79V"
"4.28V"
–
3.0V to
4.0V to
4.5V to
"2.57V"
"2.87V"
"3.86V"
"4.35V"
2.7V to
3.0V to
4.0V to
4.5V to
* The minimum operating VDD value specifies the approximate lower limit of the VDD value beyond which
the selected POR release level or LVD reset level cannot be effected without generating a reset.
1)
LVD reset function option
When “Enable” is selected, a reset is generated at the voltage that is selected by the LVD reset level
option.
Note 1: In this configuration, an operating current of several μA always flows in all modes.
No LVD reset is generated when "Disable" is selected.
Note 2: In this configuration, no operating current flows in all modes.
* See the sample operating waveforms of the reset circuit shown in Subsection 4.6.5 for details.
2)
LVD reset level option
The LVD reset level can be selected from 3 level values only when “Enable” is selected in the LVD
reset function options. Select the appropriate detection level according to the user's operating
conditions.
3)
POR release level option
The POR release level can be selected from 4 level values only when “Disable” is selected in the
LVD reset function options. When not using the internal reset circuit, set the POR release level to the
lowest level (2.57V) that will not affect the minimum guaranteed operating voltage.
Note 3: No operating current flows when the POR reset state is released.
Note 4: See the notes on the use of the internal reset circuit in paragraph 2) of Subsection 4.6.6 when
selecting a POR release level that is lower than the minimum guaranteed operating voltage
(2.57V).
4-30
LC87BK00 Chapter 4

Selection
example 1
Selecting the optimum LVD reset level to keep the microcontroller running without resetting it until VDD
falls below 3.0V according to the set's requirements
Set the LVD reset function option to "Enable" and select "2.81V" as the LVD reset
level.
Set operating range
VDD=3.0V
LVD release voltage (LVDET+LVHYS)
LVD reset voltage (LVDET=Typ. 2.81V)


Selection
example 2
Selecting the optimum LVD reset level that meets the guaranteed operating conditions of VDD= 2.7V/
Tcyc=250 ns
Set the LVD reset function option to "Enable" and select "2.81V" as the LVD reset
level.
Microcontroller operation guaranteed range
(VDD=2.7V to 5.5V/Tcyc=250ns)
LVD release voltage (LVDET+LVHYS)
LVD reset voltage (LVDET=Typ. 2.81V)
Operation guaranteed voltage lower
limit (VDD=2.7V /Tcyc=250ns)


Selection
example 3
Disabling the internal reset circuit and using an external reset IC that can detect and react at 3.0V (see also
paragraph 1) of Subsection 4.6.7)
Set the LVD reset function option to "Disable" and select "2.57V" as the POR release
level.
Set operating range
VDD=3.1V
External 3.0V detection circuit
POR release voltage
(PORRL=Typ. 2.57V)
Note 5: The operation guaranteed values (voltage/operating frequency) shown in the examples vary with
the microcontroller type. Be sure to see the latest “Semiconductor Data Sheet” and select the
appropriate setting level.
4-31
Internal Reset
4.6.5
1)
Sample Operating Waveforms of the Internal Reset Circuit
Waveform observed when only POR is used (LVD not used)
(Reset pin: Pull-up resistor RRES only)
POR release voltage
(a)
(b)
(PORRL)
VDD
Reset period
100μs or longer
Reset period
Reset undefined
state (POUKS)
RES#
• There exists an undefined state (POUKS) before the POR transistor starts functioning normally.
• The POR function generates a reset only when the power is turned on starting at the VSS level. The
reset release voltage in this case may have some range. Refer to the latest “Semiconductor Data
Sheet” for details.
• No stable reset will be generated if power is turned on again if the power level does not go down to
the VSS level as shown in (a). If such a case is anticipated, use the LVD function together as
explained in 2) or implement an external reset circuit.
• A reset is generated only when the power level goes down to the VSS level and power is turned on
again after this condition continues for 100µs or longer as shown in (b).
2)
Waveform observed when both POR and LVD functions are used
(Reset pin: Pull-up resistor RRES only)
LVD hysteresis width
LVD release voltage
(LVHYS)
(LVDET+LVHYS)
VDD
LVD reset voltage
(LVDET)
Reset period
Reset period
Reset period
Reset undefined
state (LVUKS)
RES#
• There also exists an undefined state (LVUKS) before the transistor starts functioning normally when
both POR and LVD functions are used.
• Resets are generated both when power is turned on and when the power level lowers. The reset release
voltage and entry voltage in this case may have some range. Refer to the latest “Semiconductor Data
Sheet” for details.
• A hysteresis width (LVHYS) is provided to prevent repetitions of reset release and entry cycles near
the detection level.
4-32
LC87BK00 Chapter 4
4.6.6
1)
Notes on the Use of the Internal Reset Circuit
When generating resets only with the internal POR function
When generating resets using only the internal POR function, do not short the reset pin directly to
VDD as when using it with the LVD function. Be sure to use an external capacitor CRES of an
appropriate capacitance and a pull-up resistor RRES or a pull-up resistor RRES alone. Test the circuit
extensively under the anticipated power supply conditions to verify that resets are reliably generated.
Microcontroller
RRES
RES
Reset
CRES
From POR
Figure 4.6.2. Reset Circuit Configuration Using Only the Internal POR Function
2)
When selecting a release voltage level of 2.57V only with the internal POR function
When selecting an internal POR release level of 2.57V, connect the external capacitor CRES and
pull-up resistor RRES of the values that match the power supply rise time to the reset pin and make
necessary adjustments so that the reset state is released after the release voltage exceeds the
minimum guaranteed operating voltage. Alternatively, set and hold the voltage level of the reset pin
at the low level until the release voltage exceeds the minimum guaranteed operating voltage.
When POR release level
is 2.57V
Min. guaranteed operating voltage
VDD
Reset VIH level
Reset undefined state
Reset period
(LVUKS)
RES
Figure 4.6.3.
Sample Release Level Waveform in Internal POR Only Configuration
4-33
Internal Reset
3)
When temporary power interruptions or voltage fluctuations shorter than several hundred s are
anticipated
The response time measured from the time the LVD detects a power voltage drop at the
option-selected level until it generates a reset signal is defined as the minimum low voltage detection
width TLVDW shown in Figure 4.6.4 (see “Semiconductor Data Sheet”). If temporary power
interruptions or voltage fluctuations shorter than this minimum low voltage detection width are
anticipated, be sure to take the preventive measures shown in Figure 4.6.5 or other necessary
measures.
VDD
LVD release voltage
LVD reset voltage
LVDET-0.5V
(LVDET)
TLVDW
VSS
Figure 4.6.4. Example of Power Interruption or Voltage Fluctuation Waveform
Microcontroller
VDD1
Power
supply
VSS1
RES
Figure 4.6.5. Example of Power Interruption/Voltage Fluctuation Countermeasures
4-34
LC87BK00 Chapter 4
4.6.7
1)
Notes to be Taken When Not Using the Internal Reset Circuit
When configuring an external reset IC without using the internal reset circuit
The internal POR function is activated and the capacitor CRES discharging N-channel transistor
connected to the reset pin turns on when power is turned on even if the internal reset circuit is not
used. For this reason, when connecting an external reset IC, adopt a reset IC of a type whose
detection level is not lower than the minimum guaranteed operating voltage level, and select the
lowest POR release level (2.57V) that does not affect the minimum guaranteed operating voltage.
The figures provided below show sample reset circuit configurations that use reset ICs of N-channel
open drain and CMOS types, respectively.
Reset IC
N-channel open
drain type
Microcontroller
Several
hundred
kΩ
RES
Reset
From POR
Figure 4.6.6. Sample Reset Circuit Configuration Using an N-channel Open Drain Type Reset IC
Reset IC
Insert a protective resistor of
several to dozens of kΩ to
prevent through current.
Microcontroller
CMOS type
RES
Reset
From POR
Figure 4.6.7. Sample Reset Circuit Configuration Using a CMOS Type Reset IC
4-35
Internal Reset
2)
When configuring the external POR circuit without using the internal reset circuit
The internal POR function is activated when power is turned on even if the internal reset circuit is
not used as in case 1) in Subsection 4.6.7. When configuring an external POR circuit with a CRES
value of 0.1µF or larger to obtain a longer reset period than with the internal POR, however, be sure
to connect an external diode DRES as shown in Figure 4.6.8.
Microcontroller
DRES
RRES
RES
Reset
CRES
From POR
Connect an
external diode.
Figure 4.6.8.
Sample External POR Circuit Configuration
4-36
Appendixes
Table of Contents
Appendix-I
• Special Function Register (SFR) Map
Appendix-II
•
•
•
•
•
Port 0 Block Diagram
Port 1 Block Diagram
Port 2 Block Diagram
Port 7 Block Diagram
Port 1 and Port 7 (Interrupt) Block Diagram
Appendix-III
• LC872000/LC87B000 Series On-chip Debugger Pin Treatment Guide
LC87BK00 APPENDIX-I
Address
Initial Value
R/W
LC87BK00
0-00FF
XXXX XXXX
R/W
RAM256B
FE00
0000 0000
R/W
FE01
0000 0000
R/W
FE02
0000 0000
FE06
Remarks
BIT8
BIT7
BIT6
BIT5
BIT4
BIT3
BIT2
BIT1
BIT0
AREG
-
AREG7
AREG6
AREG5
AREG4
AREG3
AREG2
AREG1
AREG0
BREG
-
BREG7
BREG6
BREG5
BREG4
BREG3
BREG2
BREG1
BREG0
R/W
CREG
-
CREG7
CREG6
CREG5
CREG4
CREG3
CREG2
CREG1
CREG0
0000 0000
R/W
PSW
-
CY
AC
PSWB5
PSWB4
LDCBNK
OV
P1
PARITY
FE07
HHHH H000
R/W
PCON
FE08
0000 HH00
R/W
IE
FE09
0000 0000
R/W
FE0A
0000 0000
R/W
FE0B
0000 0000
FE0C
HHHH H000
FE0D
FE0E
9 bits long
FE03
FE04
FE05
-
-
-
-
-
-
XTIDLE
PDN
IDLE
-
IE7
XFLG
HFLG
LFLG
-
-
XCNT1
XCNT0
IP
-
IP4B
IP43
IP3B
IP33
IP2B
IP23
IP1B
IP13
SPL
-
SP7
SP6
SP5
SP4
SP3
SP2
SP1
SP0
R/W
SPH
-
SP15
SP14
SP13
SP12
SP11
SP10
SP9
SP
R/W
CLKDV
-
-
-
-
-
-
CLKDV2
CLKDV1
CLKDV0
00HH HHHH
R/W
MRCR
-
MRCSEL
MRDST
-
-
-
-
-
-
0000 XX00
R/W
OCR
(Bits 3-2 are R/O)
-
CLKSGL
EXTOSC
CLKCB5
CLKCB4
XT2IN
XT1IN
RCSTOP
CFSTOP
FE10
0000 0000
R/W
T0CNT
Timer 0 control
-
T0HRUN
T0LRUN
T0LONG
T0LEXT
T0HCMP
T0HIE
T0LCMP
T0LIE
FE11
0000 0000
R/W
T0PRR
-
T0PRR7
T0PRR6
T0PRR5
T0PRR4
T0PRR3
T0PRR2
T0PRR1
T0PRR0
FE12
0000 0000
R
T0L
-
T0L7
T0L6
T0L5
T0L4
T0L3
T0L2
T0L1
T0L0
FE13
0000 0000
R
T0H
-
T0H7
T0H6
T0H5
T0H4
T0H3
T0H2
T0H1
T0H0
FE14
0000 0000
R/W
T0LR
-
T0LR7
T0LR6
T0LR5
T0LR4
T0LR3
T0LR2
T0LR1
T0LR0
FE15
0000 0000
R/W
T0HR
-
T0HR7
T0HR6
T0HR5
T0HR4
T0HR3
T0HR2
T0HR1
T0HR0
FE16
XXXX XXXX
R
T0CAL
-
T0CAL7
T0CAL6
T0CAL5
T0CAL4
T0CAL3
T0CAL2
T0CAL1
T0CAL0
FE17
XXXX XXXX
R
T0CAH
-
T0CAH7
T0CAH6
T0CAH5
T0CAH4
T0CAH3
T0CAH2
T0CAH1
T0CAH0
FE18
0000 0000
R/W
T1CNT
-
T1HRUN
T1LRUN
T1LONG
T1PWM
T1HCMP
T1HIE
T1LCMP
T1LIE
FE19
0000 0000
R/W
T1PRR
-
T1HPRE
T1HPRC2
T1HPRC1
T1HPRC0
T1HCMP
T1HIE
T1LCMP
T1LIE
FE1A
0000 0000
R
T1L
-
T1L7
T1L6
T1L5
T1L4
T1L3
T1L2
T1L1
T1L0
FE1B
0000 0000
R
T1H
-
T1H7
T1H6
T1H5
T1H4
T1H3
T1H2
T1H1
T1H0
FE1C
0000 0000
R/W
T1LR
-
T1LR7
T1LR6
T1LR5
T1LR4
T1LR3
T1LR2
T1LR1
T1LR0
FE1D
0000 0000
R/W
T1HR
-
T1HR7
T1HR6
T1HR5
T1HR4
T1HR3
T1HR2
T1HR1
T1HR0
(Bits 6-4 are R/O)
FE0F
Timer 1 control
AI-1
Address
Initial Value
R/W
LC87BK00
Remarks
FE34
0000 0000
R/W
SCON1
SIO1 control
FE35
00000 0000
R/W
SBUF1
9-bit register
FE36
0000 0000
R/W
SBR1
BIT8
BIT7
BIT6
BIT5
BIT4
BIT3
BIT2
BIT1
BIT0
-
SI1M1
SI1M0
SI1RUN
SI1REC
SI1DIR
SI1OVR
SI1END
SI1IE
FE1E
FE1F
FE20
FE21
FE22
FE23
FE24
FE25
FE26
FE27
FE28
FE29
FE2A
FE2B
FE2C
FE2D
FE2E
FE2F
FE30
FE31
FE32
FE33
SBUF18
SBUF17
SBUF16
SBUF15
SBUF14
SBUF13
SBUF12
SBUF11
SBUF10
-
SBRG17
SBRG16
SBRG15
SBRG14
SBRG13
SBRG12
SBRG11
SBRG10
FE37
FE38
FE39
FE3A
FE3B
FE3C
FE3D
AI-2
LC87BK00 APPENDIX-I
Address
Initial Value
R/W
LC87BK00
FE40
0000 0000
R/W
FE41
0000 0000
FE42
00HH 0000
FE43
FE44
Remarks
BIT8
BIT7
BIT6
BIT5
BIT4
BIT3
BIT2
BIT1
BIT0
P0
-
P07
P06
P05
P04
P03
P02
P01
P00
R/W
P0DDR
-
P0HPUS
P0LPUS
P0FLG
P0IE
P0HPU
P0LPU
P0HDDR
P0LDDR
R/W
P0FCR
-
T7OE
T6OE
-
-
CLKOEN
CKODV2
CKODV1
CKODV0
0000 0000
R/W
XT2PC
-
XT2PCB7
XT2PCB6
XT2PCB5
XT2PCB4
XTCFIN
XT2PCB2
XT2PCB1
XT2PCB0
0000 0000
R/W
P1
-
P17
P16
P15
P14
P13
P12
P11
P10
FE45
0000 0000
R/W
P1DDR
-
P17DDR
P16DDR
P15DDR
P14DDR
P13DDR
P12DDR
P11DDR
P10DDR
FE46
0000 0000
R/W
P1FCR
-
P17FCR
P16FCR
P15FCR
P14FCR
P13FCR
P12FCR
P11FCR
P10FCR
FE47
0000 H0H0
R/W
P1TST
-
FIXO
FIX0
MRCSHIFT
FIX0
-
DSNKOT
-
FIXO
FE48
HHHH HH00
R/W
P2
-
-
-
-
-
-
-
P21
P20
FE49
HHHH HH00
R/W
P2DDR
-
-
-
-
-
-
-
P21DDR
P20DDR
FE4A
0000 0000
R/W
I45CR
-
FIX0
FIX0
FIX0
FIX0
INT4HEG
INT4LEG
INT4IF
INT4IE
FE4B
0000 0000
R/W
I45SL
-
FIX0
FIX0
FIX0
FIX0
I4SL3
I4SL2
I4SL1
I4SL0
FE58
0000 0000
R/W
ADCRC
12-bit AD control
-
ADCHSEL3
ADCHSEL2
ADCHSEL1
ADCHSEL0
ADCR3
ADSTART
ADENDF
ADIE
FE59
0000 0000
R/W
ADMRC
12-bit AD mode
-
ADMD4
ADMD3
ADMD2
ADMD1
ADMD0
ADMR2
ADTM1
ADTM0
FE5A
0000 0000
R/W
ADRLC
12-bit AD conversion result L
-
DATAL3
DATAL2
DATAL1
DATAL0
ADRL3
ADRL2
ADRL1
ADTM2
FE5B
0000 0000
R/W
ADRHC
12-bit AD conversion result H
-
DATA7
DATA6
DATA5
DATA4
DATA3
DATA2
DATA1
DATA0
FE5C
HHH0 HHH0
R/W
P7
FE5D
0000 0000
R/W
I01CR
FE3E
FE3F
INT4/INT5 control
FE4C
FE4D
FE4E
FE4F
FE50
FE51
FE52
FE53
FE54
FE55
FE56
FE57
INT0/INT1 control
-
-
-
-
P70DDR
-
-
-
P70DT
-
INT1LH
INT1LV
INT1IF
INT1IE
INT0LH
INT0LV
INT0IF
INT0IE
AI-3
Address
Initial Value
R/W
LC87BK00
FE5E
0000 0000
R/W
I23CR
Remarks
FE5F
0000 0000
R/W
ISL
FE78
0000 0000
R/W
T67CNT
Timer 6/timer 7 control
-
T7C1
T7C0
T6C1
T6C0
T7OV
T7IE
T6OV
T6IE
FE79
0000 0000
R/W
WDTCNT
Watchdog timer control
-
WDTRSTF
WDTCKSL
WDTRUN
IDLOP1
IDLOP0
WDTSL2
WDTSL1
WDTSL0
FE7A
0000 0000
R/W
T6R
-
T6R7
T6R6
T6R5
T6R4
T6R3
T6R2
T6R1
T6R0
FE7B
0000 0000
R/W
T7R
-
T7R7
T7R6
T7R5
T7R4
T7R3
T7R2
T7R1
T7R0
FE7C
HHHH H000
R/W
SLWRC
-
-
-
-
-
-
CFLAMP
SLRCSEL
SLRCSTAT
INT2/INT3 control
BIT8
BIT7
BIT6
BIT5
BIT4
BIT3
BIT2
BIT1
BIT0
-
INT3HEG
INT3LEG
INT3IF
INT3IE
INT2HEG
INT2LEG
INT2IF
INT2IE
-
ST0HCP
ST0LCP
BTIMC1
BTIMC0
BUZON
NFSEL
NFON
ST0IN
FE60
FE61
FE62
FE63
FE64
FE65
FE66
FE67
FE68
FE69
FE6A
FE6B
FE6C
FE6D
FE6E
FE6F
FE70
FE71
FE72
FE73
FE74
FE75
FE76
FE77
AI-4
LC87BK00 APPENDIX-I
Address
Initial Value
R/W
LC87BK00
Remarks
BIT8
BIT7
BIT6
BIT5
BIT4
BIT3
BIT2
BIT1
BIT0
FE7E
0000 0000
R/W
FSR0
FLASH control (bit4 is R/0)
-
FSR0B7
Fix to 0
FSR0B6
Fix to 0
FSAERR
FSWOK
INTHIGH
FSLDAT
FSPGL
FSWREQ
FE7F
0000 0000
R/W
BTCR
Base timer control
-
BTFST
BTON
BTC11
BTC10
BTIF1
BTIE1
BTIF0
BTIE0
FE7D
FE80
FE81
FE82
FE83
FE84
FE85
FE86
FE87
FE88
FE89
FE8A
FE8B
FE8C
FE8D
FE8E
FE8F
FE90
FE91
FE92
FE93
FE94
FE95
FE96
FE97
FE98
FE99
FE9A
FE9B
AI-5
Address
Initial Value
R/W
LC87BK00
Remarks
BIT8
BIT7
FE9C
FE9D
FE9E
FE9F
FEA0
FEA1
FEA2
FEA3
FEA4
FEA5
FEA6
FEA7
FEA8
FEA9
FEAA
FEAB
FEAC
FEAD
FEAE
FEAF
FEB0
FEB1
FEB2
FEB3
FEB4
FEB5
FEB6
FEB7
FEB8
FEB9
FEBA
FEBB
AI-6
BIT6
BIT5
BIT4
BIT3
BIT2
BIT1
BIT0
LC87BK00 APPENDIX-I
Address
Initial Value
R/W
LC87BK00
Remarks
BIT8
BIT7
FEBC
FEBD
FEBE
FEBF
FEC0
FEC1
FEC2
FEC3
FEC4
FEC5
FEC6
FEC7
FEC8
FEC9
FECA
FECB
FECC
FECD
FECE
FECF
FED0
FED1
FED2
FED3
FED4
FED5
FED6
FED7
FED8
FED9
FEDA
FEDB
AI-7
BIT6
BIT5
BIT4
BIT3
BIT2
BIT1
BIT0
AI-8
LC87BK00 APPENDIX-II
Hi-PU
Bus
Low-PU
T7OUT(P07),
T6OUT(P06)
CLKOUT(P05)
P0 (FE40)
bits 7- 5
SW
S
E
L
SW
D
CMOS
or
Nch-OD
Q
W-P0
C
Pin
P07- P05
S
E
L
AD input
(AN6 - AN5)
R-P0
Hi-PU
Low-PU
SW
SW
P0 (FE40)
bit 4
D
CMOS
or
Nch-OD
Q
C
Pin
P04
S
E
L
AD input
(AN4)
Low-PU
Hi-PU
SW
SW
P0 (FE40)
bits 3-0
D
CMOS
or
Nch-OD
Q
C
Pin
P03- P00
S
E
L
AD input
(AN3 - AN0)
7
6
5
4
3
2
1
0
P0DDR(FE41)
Port
P07
P06
Pull-up resistor is:
Not attached if N-channel-OD option is
selected.
Programmable if CMOS option is
selected.
P05
P04
P03
P02
P01
P00
Special Function Input
None
AD analog 6 input
AD analog 5 input
AD analog 4 input
AD analog 3 input
AD analog 2 input
AD analog 1 input
AD analog 0 input
Function Output
Timer 7 toggle output
Timer 6 toggle output
Clock output
None
None
None
None
None
Table of Port 0 Multiplexed Functions
Port 0 Block Diagram
Option: Output type (CMOS or N-channel OD) selectable in 1-bit units
AII-1
Port Block Diagrams
P0DDR(FE41)
-
-
5
4
3
2
1
0
Int. request to
vector 0004B
P0(FE40) bit 7
P07 pin input data
P0 interrupt detect
P0(FE40) bit 6
P06 pin input data
P0(FE40) bit 5
P05 pin input data
P0(FE40) bit 4
P04 pin input data
P0 interrupt detect
P0DDR(FE41) bit 1
P0(FE40) bit 3
P03 pin input data
P0(FE40) bit 2
P02 pin input data
P0(FE40) bit 1
P01 pin input data
P0(FE40) bit 0
P00 pin input data
P0DDR(FE41) bit 0
Port 0 (Interrupt) Block Diagram
AII-2
LC87BK00 APPENDIX-II
Function outputs 7- 6
P1FCR (FE46)
bits 7 - 6
D
W-P1FCR
Q
C
Bus
Low-PU
R-P1FCR
SW
P1 (FE44)
bits 7 - 6
CMOS
or
Nch-OD
D
W-P1
C
Q
Pin
XOR
P17,P16
S
E
L
R-P1
INT2,INT1
P1DDR (FE45)
bits 7 - 6
D
W-P1DDR
Q
C
Port
P17
P16
P15
P14
P13
R-P1DDR
FUNCTION outputs 5 - 3
Special Function Input
INT1/timer 0H capture input
INT2/timer 0 pulse input
INT3/SIO1 clock/timer 0 event input
SIO1 data input
None
Function Output
Timer 1HPWM output
Timer 1LPWM output
SIO1 clock output
SIO1 data output
SIO1 data output
Table of Port 1 Multiplexed Functions
P1FCR (FE46)
bits 5 - 0
D
W-P1FCR
Q
C
Bus
Low-PU
R-P1FCR
SW
P1 (FE44)
bits 5 - 0
CMOS
or
Nch-OD
D
W-P1
C
Q
OR
S
E
L
R-P1
Pin
P15 - P10
Special input
INT3(P15)
P1DDR (FE45)
bits 5 - 0
D
W-P1DDR
Q
C
R-P1DDR
Port 1 Block Diagram
Option: Output type (CMOS or N-channel OD) selectable in 1-bit units
AII-3
Bus
Port Block Diagrams
Low-PU
SW
P2 (FE48)
bits 1 - 0
D
CMOS
or
Nch-OD
Q
W-P2
C
Pin
P21,P20
S
E
L
Special input
R-P2
INT4(P21,P20)
P2DDR (FE49)
bits 1 - 0
D
W-P2DDR
Q
C
R-P2DDR
Port
P21
P20
Function Output
None
Special Function Input
INT4/timer 0L capture/timer 0H capture input
INT4/timer 0L capture/timer 0H capture input
None
Table of Port 2 Multiplexed Functions
Port 2 Block Diagram
Option: Output type (CMOS or N-channel-OD) selectable in 1-bit units
Int. request to
vector 00013
7
6
5
I45SL (FE4B)
4
3
2
1
0
7
6
5
3
2
1
0
I45CR (FE4A)
P21
P20
4
Timer 1 count clock
S
E
L
S
E
L
Port 2 （Interrupt） Block Diagram
AII-4
Timer 0L capture signal
Timer 0H capture signal
LC87BK00 APPENDIX-II
Bus
Low-PU
HALT/HOLD
SW
P7 (FE5C)
bit 0
D
W-P7
Pin
Q
P70
C
S
E
L
AD input (AN8)
INT0
R-P7
P7 (FE5C)
bit 4
D
Q
C
Port
P70
Special Function Input
INT0/timer 0L capture/AD analog 8 input
Table of Port 7 Multiplexed Functions
Port 7 Block Diagram
Option: None
AII-5
Function Output
None
Port Block Diagrams
ISL(FE5F)
7
INT3
6
5
4
3
2
1
Noise filter
Int. request to
vector 00013
7
6
5
4
3
2
1
0
S
E
L
Timer 0 clock input
S
E
L
Timer 0H capture signal
S
E
L
Timer 0L capture signal
0
I23CR(FE5E)
Int. request to
vector 0001B
INT2
INT1
H level
L level
Int. request to
vector 00003
7
6
5
4
3
2
1
0
I01CR(FE5D)
Int. request to
vector 0000B
INT0
H level
L level
Port 1 and Port 7 (Interrupt) Block Diagram
AII-6
LC87BK00 APPENDIX-III
March 9, 2011 Ver.1.10
Microcontroller Development Department
SANYO Semiconductor Co., Ltd.
LC872000/LC87B000 Series On-chip Debugger Pin Treatment Guide
1. Overview
The "LC872000/LC87B000 Series On-chip Debugger Pin Treatment Guide" describes the treatment of pins
for low-pin-count (30 pins or less) microcontrollers that are equipped with multiple on-chip debugger pin
channels.
2. Operation of On-chip Debugger Pins
On-chip debugger pins DBGPx0 to DBGPx2 are placed in the state shown below when a system reset is
performed even when no debugger is connected.
Debugger Pin Name
DBGP00/DBGP10/
DBGPX0/DBGP20
DBGP01/DBGP11
DBGP21
DBGP02/DBGP12/
DBGP22
Pin Status
Affected Products
Low-level output during
reset sequence
Low-level output for
several μs after the reset
state is released
Hi-Z (input state)
Held high by a pull-up
resistor for several μs after
the reset state is released
Hi-Z (input state)
Held high by a pull-up
resistor for several μs after
the reset state is released
LC87F2416A
LC87F2608A/LC87F2708A/LC87F2G08A/LC87F2H08A/
LC87F2R04A/LC87FBK08A/LC87FBL08A/
LC87FBG08A/LC87FBH08A
LC87F2416A
LC87F2708A
LC87F2416A
LC87F2608A/LC87F2708A/LC87F2G08A/LC87F2H08A/
LC87F2R04A/LC87FBK08A/LC87FBL08A/
LC87FBG08A/LC87FBH08A
3. Pin Treatment Procedures
For pins that also have a debugging function, it is generally necessary to mount the components that are
recommended for connection, listed in the table on page 11 of the "RD87 On-chip Debugger Installation
Guide", on the circuit board of mass production sets. Pins that are not used for onboard reprogramming on the
mass production set, however, can be treated by installing a minimum number of external components and
observing the following restriction conditions, for the reasons that are described in the previous section.
Debugger Pin Name
DBGP00/DBGP10/
DBGPX0/DBGP20
DBGP01/DBGP11/
DBGP21
DBGP02/DBGP12/
DBGP22
Pin Set Specification Restrictions and Components to Install
Input/ I/O /analog input Insert a current limiting resistor of 100Ω or more.
Output
Input / I/O /output/
analog input
Input
I/O
Output
Analog input
Unused （N.C.）
Remarks
Reference
example 1
No restrictions and no components need to be installed.
No restrictions and no components need to be installed.
Make sure that no pulses of 100 kHz or higher are input
during the system reset sequence. When a pulse of 100
kHz or more is to be input, assign the pulse signal to a
different pin.
Pull up or down the pin that is placed in the floating
(Hi-Z) state during the system reset sequence using a
100 kΩ resistor.
For LC87F2416A, pull up or down the pin using a 100
kΩ resistor.
For models other than LC87F2416A, pull up the pin
with a 100 kΩ resistor.
When the analog input impedance is high (5 k or
more) or when noise is easily superimposed onto the
analog input signal, assign the analog channel to a
different pin.
Select an N-channel open drain output port with a port
option and short-circuit the pin to VSS1 (GND) in input
mode.
Reference
example 2
Note 2
Reference
example 3
Note 2
Reference
example 4
Note 3
Note 1: The set may not operate properly after the reset is released unless it is subjected to pin treatment that
complies with the set specifications.
Note 2: Depending on the microcontroller output status, current may flow to the external pull-up or pulldown resistors when standby mode is entered, so be sure to set these pins to the same potential or HiZ before entering standby mode.
AIII-1
On-chip Debugger Pin Treatment
Note 3: Assign the DBGPx2 pins to “applications with few data changes due to digital I/O” whenever
possible.
Reference example 1
Limits the through
current during system
reset.
When Pch-Tr is
ON during system
reset
Microcontroller
interior
Pch-Tr OFF during
system reset
Nch-Tr ON during the system
reset period or for several µs
after reset is released
DBGPx0
Insert 100 
or more.
Digital input
Reference example 2
Prevents floating status
(Hi-Z) during system reset.
Pull-up resistor (several
k to 100k)
Microcontroller interior
I/O device
Nch-Tr OFF during
system reset
(Example of selecting
the Nch-OD option)
DBGPx2
Protective
resistor
Nch-OD
output
Digital input/on-chip
debugger input
Reference example 3
Prevents the floating status
(Hi-Z) during system reset.
Microcontroller interior
100 k
pull-up
resistor
Pch/Nch-Tr OFF
during system reset
DBGPx2
Digital input/on-chip
debugger input
Reference example 4
Lowers impedance to
prevent the
superimposition of noise
during system reset.
Analog voltage
Microcontroller interior
Nch-Tr OFF during
system reset
(Example of selecting
the Nch-OD option)
DBGPx2
5 k or
less
Digital input/on-chip
debugger input
Analog input
AIII-2
Important Note
This document is designed to provide the reader with accurate information in easily
understandable form regarding the device features and the correct device implementation
procedures.
The sample configurations included in the various descriptions are intended for reference
only and should not be directly incorporated in user product configurations.
ON Semiconductor shall bear no responsibility for obligations concerning patent
infringements, safety or other legal disputes arising from prototypes or actual products
created using the information contained herein.
LC87BK00 SERIES USER’S MANUAL
Rev : 1.00
October 21, 2011
ON Semiconductor
Digital Solution Division
Microcontroller & Flash Business Unit