PHILIPS P89C58X2FA

INTEGRATED CIRCUITS
P89C51X2/52X2/54X2/58X2
80C51 8-bit Flash microcontroller family
4K/8K/16K/32K Flash
128B/256B RAM
Preliminary data
Supersedes data of 2002 Feb 28
2002 Jun 05
Philips Semiconductors
Preliminary data
80C51 8-bit Flash microcontroller family
P89C51X2/52X2/54X2/58X2
4K/8K/16K/32K Flash
modes of power reduction — idle mode and power-down mode —
are available. The idle mode freezes the CPU while allowing the
RAM, timers, serial port, and interrupt system to continue
functioning. The power-down mode saves the RAM contents but
freezes the oscillator, causing all other chip functions to be
inoperative. Since the design is static, the clock can be stopped
without loss of user data. Then the execution can be resumed from
the point the clock was stopped.
DESCRIPTION
The Philips microcontrollers described in this data sheet are
high-performance static 80C51 designs. They are manufactured in
an advanced CMOS process and contain a non-volatile Flash
program memory. They support both 12-clock and 6-clock operation.
The P89C51X2 and P89C52X2/54X2/58X2 contain 128 byte RAM
and 256 byte RAM respectively, 32 I/O lines, three 16-bit
counter/timers, a six-source, four-priority level nested interrupt
structure, a serial I/O port for either multi-processor
communications, I/O expansion or full duplex UART, and on-chip
oscillator and clock circuits.
SELECTION TABLE
For applications requiring more Flash and RAM, as well as more
on-chip peripherals, see the P89C66x and P89C51Rx2 data sheets.
In addition, the devices are static designs which offer a wide range
of operating frequencies down to zero. Two software selectable
PWM
PCA
WD
UART
I 2C
CAN
SPI
ADC bits/ch.
I/O Pins
Interrupts
(External)
Program
Security
Default Clock
Rate
Optional
Clock Rate
Max.
Freq.
at 6-clk
/ 12-clk
(MHz)
P89C58X2
256B
–
–
32K
3
–
–
–
n
–
–
–
–
32
6 (2)
n
12–clk
6-clk
20/33
–
0–20/33
P89C54X2
256B
–
–
16K
3
–
–
–
n
–
–
–
–
32
6 (2)
n
12–clk
6-clk
20/33
–
0–20/33
P89C52X2
256B
–
–
8K
3
–
–
–
n
–
–
–
–
32
6 (2)
n
12–clk
6-clk
20/33
–
0–20/33
P89C51X2
128B
–
–
4K
3
–
–
–
n
–
–
–
–
32
6 (2)
n
12–clk
6-clk
20/33
–
0–20/33
RAM
# of Timers
Serial Interfaces
Flash
Timers
OTP
Memory
ROM
Type
Freq.
Range
at 3V
(MHz)
Freq.
Range
at
5V
(MHz)
NOTE:
1. I2C = Inter-Integrated Circuit Bus; CAN = Controller Area Network; SPI = Serial Peripheral Interface; PCA = Programmable Counter Array;
ADC = Analog-to-Digital Converter; PWM = Pulse Width Modulation
DEVICE COMPARISON TABLE
Item
P89C5xX2 devices (this data
sheet)
P89C5xBx devices (separate data
sheet)
P89C5xUxx devices
(discontinued)
Type Description
P89C5xX2Bxx/P89C5xX2Fxx
P89C5xBx
P89C5xUBxx/P89C5xUFxx
PROGRAMMING
ALGORITHM
When using a parallel programmer,
be sure to select P89C5xX2 devices.
IF DEVICES ARE NOT YET
SELECTABLE ASK YOUR
PROGRAMMER VENDOR FOR A
SOFTWARE UPDATE
When using a parallel programmer,
be sure to select P89C5xBx devices.
IF DEVICES ARE NOT YET
SELECTABLE ASK YOUR
PROGRAMMER VENDOR FOR A
SOFTWARE UPDATE
When using a parallel programmer,
be sure to select P89C5xUxxx
devices.
Quad Flat Package
type
LQFP package (P89C5xX2xBD)
LQFP package (P89C5xBBD)
PQFP package (P89C5xUxBB)
Package identifiers
PLCC = A
LQFP = BD
PDIP = N
PLCC = A
LQFP = BD
PDIP = P
PLCC = AA
LQFP = BB
PDIP = PN
Flash Memory program
and erase cycles
10,000 program and erase cycles
10,000 program and erase cycles
100 program and erase cycles
2002 Jun 06
2
Philips Semiconductors
Preliminary data
80C51 8-bit Flash microcontroller family
P89C51X2/52X2/54X2/58X2
4K/8K/16K/32K Flash
• LQFP, PLCC or DIP package
• Extended temperature ranges
• Dual Data Pointers
• Three security bits
• Four interrupt priority levels
• Six interrupt sources
• Four 8-bit I/O ports
• Full-duplex enhanced UART
FEATURES
• 80C51 Central Processing Unit
– 4 Kbytes Flash (P89C51X2)
– 8 Kbytes Flash (P89C52X2)
– 16 Kbytes Flash (P89C54X2)
– 32 Kbytes Flash (P89C58X2)
– 128 byte RAM (P89C51X2)
– 256 byte RAM (P89C52/54X2/58X2)
– Boolean processor
– Fully static operation
• 12-clock operation with selectable 6-clock operation (via software
– Framing error detection
or via parallel programmer)
– Automatic address recognition
• Memory addressing capability
• Three 16-bit timers/counters T0, T1 (standard 80C51) and
– Up to 64 Kbytes ROM and 64 Kbytes RAM
additional T2 (capture and compare)
• Power control modes:
• Programmable clock-out pin
• Asynchronous port reset
• Low EMI (inhibit ALE, slew rate controlled outputs, and 6-clock
– Clock can be stopped and resumed
– Idle mode
– Power-down mode
mode)
• Two speed ranges
• Wake-up from Power Down by an external interrupt
– 0 to 20 MHz with 6-clock operation
– 0 to 33 MHz with 12-clock operation
2002 Jun 06
3
Philips Semiconductors
Preliminary data
80C51 8-bit Flash microcontroller family
P89C51X2/52X2/54X2/58X2
4K/8K/16K/32K Flash
P89C51X2 ORDERING INFORMATION (4 KBYTE FLASH)
Type number
Package
Name
Description
Version
Temperature
R
Range
(°C)
P89C51X2BA
PLCC44
plastic leaded chip carrier; 44 leads
SOT187-2
0 to +70
P89C51X2BN
DIP40
plastic dual in-line package; 40 leads (600 mil)
SOT129-1
0 to +70
P89C51X2BBD
LQFP44
plastic low profile quad flat package; 44 leads
SOT389-1
0 to +70
P89C51X2FA
PLCC44
plastic leaded chip carrier; 44 leads
SOT187-2
–40 to +85
P89C52X2 ORDERING INFORMATION (8 KBYTE FLASH)
Type number
Package
Name
Description
Version
Temperature
R
Range
(°C)
P89C52X2BA
PLCC44
plastic leaded chip carrier; 44 leads
SOT187-2
0 to +70
P89C52X2BN
DIP40
plastic dual in-line package; 40 leads (600 mil)
SOT129-1
0 to +70
P89C52X2BBD
LQFP44
plastic low profile quad flat package; 44 leads
SOT389-1
0 to +70
P89C52X2FA
PLCC44
plastic leaded chip carrier; 44 leads
SOT187-2
–40 to +85
P89C52X2FN
DIP40
plastic dual in-line package; 40 leads (600 mil)
SOT129-1
–40 to +85
P89C52X2FBD
LQFP44
plastic low profile quad flat package; 44 leads
SOT389-1
–40 to +85
P89C54X2 ORDERING INFORMATION (16 KBYTE FLASH)
Type number
Package
Name
Description
Version
Temperature
R
Range
(°C)
P89C54X2BA
PLCC44
plastic lead chip carrier; 44 leads
SOT187-2
0 to +70
P89C54X2BN
DIP40
plastic dual in-line package; 40 leads (600 mil)
SOT129-1
0 to +70
P89C54X2BBD
LQFP44
plastic low profile quad flat package; 44 leads
SOT389-1
0 to +70
P89C54X2FA
PLCC44
plastic lead chip carrier; 44 leads
SOT187-2
–40 to +85
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P89C58X2 ORDERING INFORMATION (32 KBYTE FLASH)
Type number
Name
Description
Version
Temperature
R
Range
(°C)
P89C58X2BA
PLCC44
plastic lead chip carrier; 44 leads
SOT187-2
0 to +70
P89C58X2BN
DIP40
plastic dual in-line package; 40 leads (600 mil)
SOT129-1
0 to +70
P89C58X2BBD
LQFP44
plastic low profile quad flat package; 44 leads
SOT389-1
0 to +70
P89C58X2FA
PLCC44
plastic lead chip carrier; 44 leads
SOT187-2
–40 to +85
2002 Jun 06
Package
4
Philips Semiconductors
Preliminary data
80C51 8-bit Flash microcontroller family
P89C51X2/52X2/54X2/58X2
4K/8K/16K/32K Flash
PART NUMBER DERIVATION
Memory
P89C51X2
9 = Flash
1 = 128 BYTES RAM
4 KBYTES FLASH
2 = 256 BYTES RAM
8 KBYTES FLASH
4 = 256 BYTES RAM
16 KBYTES FLASH
8 = 256 BYTES RAM
32 KBYTES FLASH
Temperature Range
Package
B = 0 °C TO +70 °C
F = –40 °C TO +85 °C
A = PLCC
N = DIP
BD = LQFP
X2 = 6-clock
mode available
The following table illustrates the correlation between operating mode, power supply and maximum external clock frequency:
Operating Mode
Power Supply
Maximum Clock Frequency
6-clock
5 V ± 10%
20 MHz
12-clock
5 V ± 10%
33 MHz
2002 Jun 06
5
Philips Semiconductors
Preliminary data
80C51 8-bit Flash microcontroller family
P89C51X2/52X2/54X2/58X2
4K/8K/16K/32K Flash
BLOCK DIAGRAM 1
ACCELERATED 80C51 CPU
(12-CLK MODE, 6-CLK MODE)
0K / 4K / 8K / 16K /
32 KBYTE
CODE FLASH
FULL-DUPLEX
ENHANCED UART
128 / 256 BYTE
DATA RAM
TIMER 0
TIMER 1
PORT 3
CONFIGURABLE I/Os
TIMER 2
PORT 2
CONFIGURABLE I/Os
PORT 1
CONFIGURABLE I/Os
PORT 0
CONFIGURABLE I/Os
CRYSTAL OR
RESONATOR
OSCILLATOR
su01617
2002 Jun 06
6
Philips Semiconductors
Preliminary data
80C51 8-bit Flash microcontroller family
P89C51X2/52X2/54X2/58X2
4K/8K/16K/32K Flash
BLOCK DIAGRAM 2 (CPU-ORIENTED)
P0.0–P0.7
P2.0–P2.7
PORT 0
DRIVERS
PORT 2
DRIVERS
VCC
VSS
RAM ADDR
REGISTER
PORT 0
LATCH
RAM
PORT 2
LATCH
ROM/EPROM
8
B
REGISTER
STACK
POINTER
ACC
PROGRAM
ADDRESS
REGISTER
TMP1
TMP2
BUFFER
ALU
SFRs
PC
INCREMENTER
TIMERS
PSW
8
16
PSEN
ALE/PROG
EA / VPP
TIMING
AND
CONTROL
RST
INSTRUCTION
REGISTER
PROGRAM
COUNTER
PD
DPTR’S
MULTIPLE
PORT 1
LATCH
PORT 3
LATCH
PORT 1
DRIVERS
PORT 3
DRIVERS
P1.0–P1.7
P3.0–P3.7
OSCILLATOR
XTAL1
XTAL2
SU00845
2002 Jun 06
7
Philips Semiconductors
Preliminary data
80C51 8-bit Flash microcontroller family
P89C51X2/52X2/54X2/58X2
4K/8K/16K/32K Flash
LOGIC SYMBOL
PLASTIC LEADED CHIP CARRIER PIN FUNCTIONS
VCC
6
VSS
XTAL1
1
40
7
39
PORT 0
ADDRESS AND
DATA BUS
PLCC
XTAL2
17
PORT 1
T2
T2EX
RST
EA/VPP
18
Pin
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
RxD
TxD
INT0
INT1
T0
T1
WR
RD
PORT 2
ALE/PROG
PORT 3
SECONDARY FUNCTIONS
PSEN
ADDRESS BUS
SU00830
PLASTIC DUAL IN-LINE PACKAGE
PIN CONFIGURATIONS
T2/P1.0 1
39 P0.0/AD0
P1.2 3
38 P0.1/AD1
P1.3 4
37 P0.2/AD2
P1.4 5
36 P0.3/AD3
P1.5 6
35 P0.4/AD4
P1.6 7
34 P0.5/AD5
P1.7 8
33 P0.6/AD6
Pin
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
Pin
31
32
33
34
35
36
37
38
39
40
41
42
43
44
Function
P2.7/A15
PSEN
ALE
NIC*
EA/VPP
P0.7/AD7
P0.6/AD6
P0.5/AD5
P0.4/AD4
P0.3/AD3
P0.2/AD2
P0.1/AD1
P0.0/AD0
VCC
SU01062
LOW PROFILE QUAD FLAT PACK
PIN FUNCTIONS
34
1
33
LQFP
11
23
32 P0.7/AD7
DUAL
IN-LINE
PACKAGE
31 EA/VPP
12
Pin
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
30 ALE
INT0/P3.2 12
29 PSEN
INT1/P3.3 13
28 P2.7/A15
T0/P3.4 14
27 P2.6/A14
T1/P3.5 15
26 P2.5/A13
WR/P3.6 16
25 P2.4/A12
RD/P3.7 17
24 P2.3/A11
XTAL2 18
23 P2.2/A10
XTAL1 19
22 P2.1/A9
VSS 20
21 P2.0/A8
Function
P1.5
P1.6
P1.7
RST
P3.0/RxD
NIC*
P3.1/TxD
P3.2/INT0
P3.3/INT1
P3.4/T0
P3.5/T1
P3.6/WR
P3.7/RD
XTAL2
XTAL1
Pin
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
* NO INTERNAL CONNECTION
SU01063
2002 Jun 06
Function
P3.4/T0
P3.5/T1
P3.6/WR
P3.7/RD
XTAL2
XTAL1
VSS
NIC*
P2.0/A8
P2.1/A9
P2.2/A10
P2.3/A11
P2.4/A12
P2.5/A13
P2.6/A14
44
RST 9
TxD/P3.1 11
Function
NIC*
P1.0/T2
P1.1/T2EX
P1.2
P1.3
P1.4
P1.5
P1.6
P1.7
RST
P3.0/RxD
NIC*
P3.1/TxD
P3.2/INT0
P3.3/INT1
28
* NO INTERNAL CONNECTION
40 VCC
T2EX/P1.1 2
RxD/P3.0 10
29
8
22
Function
VSS
NIC*
P2.0/A8
P2.1/A9
P2.2/A10
P2.3/A11
P2.4/A12
P2.5/A13
P2.6/A14
P2.7/A15
PSEN
ALE
NIC*
EA/VPP
P0.7/AD7
Pin
31
32
33
34
35
36
37
38
39
40
41
42
43
44
Function
P0.6/AD6
P0.5/AD5
P0.4/AD4
P0.3/AD3
P0.2/AD2
P0.1/AD1
P0.0/AD0
VCC
NIC*
P1.0/T2
P1.1/T2EX
P1.2
P1.3
P1.4
SU01487
Philips Semiconductors
Preliminary data
80C51 8-bit Flash microcontroller family
P89C51X2/52X2/54X2/58X2
4K/8K/16K/32K Flash
PIN DESCRIPTIONS
PIN NUMBER
MNEMONIC DIP
VSS
20
VCC
40
P0.0-0.7
39–32
PLCC
22
44
43–36
LQFP
16
38
37–30
TYPE
I
I
I/O
P1.0–P1.7
1–8
2–9
40–44,
1–3
I/O
P2.0–P2.7
1
2
21–28
2
3
24–31
40
41
18–25
I/O
I
I/O
P3.0–P3.7
10–17
11,
13–19
5,
7–13
I/O
RST
10
11
12
13
14
15
16
17
9
11
13
14
15
16
17
18
19
10
5
7
8
9
10
11
12
13
4
I
O
I
I
I
I
O
O
I
ALE/PROG
30
33
27
O
PSEN
29
32
26
O
EA/VPP
31
35
29
I
XTAL1
19
21
15
I
NAME AND FUNCTION
Ground: 0 V reference.
Power Supply: This is the power supply voltage for normal, idle, and power-down operation.
Port 0: Port 0 is an open-drain, bidirectional I/O port. Port 0 pins that have 1s written to
them float and can be used as high-impedance inputs. Port 0 is also the multiplexed
low-order address and data bus during accesses to external program and data memory. In
this application, it uses strong internal pull-ups when emitting 1s. Port 0 also outputs the
code bytes during program verification and received code bytes during Flash programming.
External pull-ups are required during program verification.
Port 1: Port 1 is an 8-bit bidirectional I/O port with internal pull-ups. Port 1 pins that have 1s
written to them are pulled high by the internal pull-ups and can be used as inputs. As inputs,
port 1 pins that are externally pulled low will source current because of the internal pull-ups.
(See DC Electrical Characteristics: IIL). Port 1 also receives the low-order address byte
during program memory verification. Alternate functions for Port 1 include:
T2 (P1.0): Timer/Counter 2 external count input/clockout (see Programmable Clock-Out)
T2EX (P1.1): Timer/Counter 2 Reload/Capture/Direction control
Port 2: Port 2 is an 8-bit bidirectional I/O port with internal pull-ups. Port 2 pins that have 1s
written to them are pulled high by the internal pull-ups and can be used as inputs. As inputs,
port 2 pins that are externally being pulled low will source current because of the internal
pull-ups. (See DC Electrical Characteristics: IIL). Port 2 emits the high-order address byte
during fetches from external program memory and during accesses to external data memory
that use 16-bit addresses (MOVX @DPTR). In this application, it uses strong internal
pull-ups when emitting 1s. During accesses to external data memory that use 8-bit addresses
(MOV @Ri), port 2 emits the contents of the P2 special function register. Some Port 2 pins
receive the high order address bits during Flash programming and verification.
Port 3: Port 3 is an 8-bit bidirectional I/O port with internal pull-ups. Port 3 pins that have 1s
written to them are pulled high by the internal pull-ups and can be used as inputs. As inputs,
port 3 pins that are externally being pulled low will source current because of the pull-ups.
(See DC Electrical Characteristics: IIL). Port 3 also serves the special features of the 80C51
family, as listed below:
RxD (P3.0): Serial input port
TxD (P3.1): Serial output port
INT0 (P3.2): External interrupt
INT1 (P3.3): External interrupt
T0 (P3.4): Timer 0 external input
T1 (P3.5): Timer 1 external input
WR (P3.6): External data memory write strobe
RD (P3.7): External data memory read strobe
Reset: A high on this pin for two machine cycles while the oscillator is running, resets the
device. An internal diffused resistor to VSS permits a power-on reset using only an external
capacitor to VCC.
Address Latch Enable/Program Pulse: Output pulse for latching the low byte of the
address during an access to external memory. In normal operation, ALE is emitted at a
constant rate of 1/6 (12-clk) or 1/3 (6-clk Mode) the oscillator frequency, and can be used for
external timing or clocking. Note that one ALE pulse is skipped during each access to
external data memory. This pin is also the program pulse input (PROG) during Flash
programming. ALE can be disabled by setting SFR auxiliary.0. With this bit set, ALE will be
active only during a MOVX instruction.
Program Store Enable: The read strobe to external program memory. When the device is
executing code from the external program memory, PSEN is activated twice each machine
cycle, except that two PSEN activations are skipped during each access to external data
memory. PSEN is not activated during fetches from internal program memory.
External Access Enable/Programming Supply Voltage: EA must be externally held low to enable the device
to fetch code from external program memory locations 0000H to 0FFFH/1FFFH/3FFFH/7FFFH. If EA is held
high, the device executes from internal program memory unless the program counter contains an address
greater than the on-chip Flash. This pin also receives the 5 V / 12 V programming supply voltage (VPP) during
Flash programming. If security bit 1 is programmed, EA will be internally latched on Reset.
Crystal 1: Input to the inverting oscillator amplifier and input to the internal clock generator
circuits.
Crystal 2: Output from the inverting oscillator amplifier.
XTAL2
18
20
14
O
NOTE:
To avoid “latch-up” effect at power-on, the voltage on any pin at any time must not be higher than VCC + 0.5 V or VSS – 0.5 V, respectively.
2002 Jun 06
9
Philips Semiconductors
Preliminary data
80C51 8-bit Flash microcontroller family
P89C51X2/52X2/54X2/58X2
4K/8K/16K/32K Flash
Table 1.
SYMBOL
Special Function Registers
DESCRIPTION
DIRECT
ADDRESS
ACC*
AUXR#
AUXR1#
B*
CKCON
DPTR:
DPH
DPL
Accumulator
Auxiliary
Auxiliary 1
B register
Clock Control Register
Data Pointer (2 bytes)
Data Pointer High
Data Pointer Low
E0H
8EH
A2H
F0H
8FH
IE*
Interrupt Enable
A8H
MSB
BIT ADDRESS, SYMBOL, OR ALTERNATIVE PORT FUNCTION
LSB
E7
E6
E5
E4
E3
E2
E1
E0
–
–
–
–
–
–
–
–
–
WUPD
–
0
–
–
AO
DPS
F7
F6
F5
F4
F3
F2
F1
F0
–
–
–
–
–
–
–
X2
83H
82H
AF
AE
AD
AC
AB
AA
A9
A8
EA
–
ET2
ES
ET1
EX1
ET0
EX0
BF
BE
BD
BC
BB
BA
B9
B8
–
–
PT2
PT2H
PS
PSH
PT1
PT1H
PX1
PX1H
PT0
PT0H
PX0
PX0H
Interrupt Priority
Interrupt Priority High
B8H
B7H
–
–
87
86
85
84
83
82
81
80
P0*
Port 0
80H
AD7
AD6
AD5
AD4
AD3
AD2
AD1
AD0
97
96
95
94
93
92
91
90
P2*
Port 1
Port 2
90H
A0H
0x000000B
xx000000B
xx000000B
FFH
–
–
–
–
–
–
T2EX
T2
A7
A6
A5
A4
A3
A2
A1
A0
AD15
AD14
AD13
AD12
AD11
AD10
AD9
AD8
B7
B6
B5
B4
B3
B2
B1
B0
T1
T0
INT1
INT0
TxD
RxD
FFH
00xx0000B
P3*
Port 3
B0H
RD
WR
PCON#1
Power Control
87H
SMOD1
SMOD0
–
POF
GF1
GF0
PD
IDL
D7
D6
D5
D4
D3
D2
D1
D0
AC
F0
RS1
RS0
OV
–
P
PSW*
RACAP2H#
RACAP2L#
SADDR#
SADEN#
SBUF
Program Status Word
Timer 2 Capture High
Timer 2 Capture Low
Slave Address
Slave Address Mask
Serial Data Buffer
D0H
CBH
CAH
A9H
B9H
99H
CY
9F
9E
9D
9C
9B
9A
99
98
SCON*
SP
Serial Control
Stack Pointer
98H
81H
SM0/FE
SM1
SM2
REN
TB8
RB8
TI
RI
8F
8E
8D
8C
8B
8A
89
88
TCON*
Timer Control
88H
TF1
TR1
TF0
TR0
IE1
IT1
IE0
IT0
CF
CE
CD
CC
CB
CA
C9
C8
T2CON*
Timer 2 Control
C8H
TF2
EXF2
RCLK
TCLK
EXEN2
TR2
C/T2
CP/RL2
T2MOD#
Timer 2 Mode Control
C9H
–
–
–
–
–
–
T2OE
DCEN
TH0
Timer High 0
8CH
TH1
Timer High 1
8DH
TH2#
Timer High 2
CDH
TL0
Timer Low 0
8AH
TL1
Timer Low 1
8BH
TL2#
Timer Low 2
CCH
TMOD
Timer Mode
89H
GATE
C/T
M1
M0
GATE
C/T
M1
M0
NOTE:
Unused register bits that are not defined should not be set by the user’s program. If violated, the device could function incorrectly.
* SFRs are bit addressable.
# SFRs are modified from or added to the 80C51 SFRs.
– Reserved bits.
1. Reset value depends on reset source.
2002 Jun 06
00H
xxxxxxx0B
xxx000x0B
00H
xxx00000B
00H
00H
IP*
IPH#
P1*
RESET
VALUE
10
FFH
FFH
000000x0B
00H
00H
00H
00H
xxxxxxxxB
00H
07H
00H
00H
xxxxxx00B
00H
00H
00H
00H
00H
00H
00H
Philips Semiconductors
Preliminary data
80C51 8-bit Flash microcontroller family
P89C51X2/52X2/54X2/58X2
4K/8K/16K/32K Flash
FLASH EPROM MEMORY
Programmable Clock-Out Pin
General Description
A 50% duty cycle clock can be programmed to be output on P1.0.
This pin, besides being a regular I/O pin, has two alternate
functions. It can be programmed:
The P89C51X2/P89C52X2/P89C54X2/P89C58X2 FLASH reliably
stores memory contents even after 10,000 erase and program
cycles. The cell is designed to optimize the erase and programming
mechanisms. In addition, the combination of advanced tunnel oxide
processing and low internal electric fields for erase and
programming operations produces reliable cycling.
1. to input the external clock for Timer/Counter 2, or
2. to output a 50% duty cycle clock ranging from 61 Hz to 4 MHz at
a 16 MHz operating frequency in 12-clock mode (122 Hz to
8 MHz in 6-clock mode).
To configure the Timer/Counter 2 as a clock generator, bit C/T2 (in
T2CON) must be cleared and bit T20E in T2MOD must be set. Bit
TR2 (T2CON.2) also must be set to start the timer.
Features
• FLASH EPROM internal program memory with Chip Erase
• Up to 64 kbyte external program memory if the internal program
The Clock-Out frequency depends on the oscillator frequency and
the reload value of Timer 2 capture registers (RCAP2H, RCAP2L)
as shown in this equation:
memory is disabled (EA = 0)
• Programmable security bits
• 10,000 minimum erase/program cycles for each byte
• 10 year minimum data retention
• Programming support available from many popular vendors
n
Oscillator Frequency
(65536–RCAP2H, RCAP2L)
Where:
n = 2 in 6-clock mode, 4 in 12-clock mode.
(RCAP2H,RCAP2L) = the content of RCAP2H and RCAP2L
taken as a 16-bit unsigned integer.
OSCILLATOR CHARACTERISTICS
In the Clock-Out mode Timer 2 roll-overs will not generate an
interrupt. This is similar to when it is used as a baud-rate generator.
It is possible to use Timer 2 as a baud-rate generator and a clock
generator simultaneously. Note, however, that the baud-rate and the
Clock-Out frequency will be the same.
Using the oscillator, XTAL1 and XTAL2 are the input and output,
respectively, of an inverting amplifier. The pins can be configured for
use as an on-chip oscillator, as shown in the logic symbol.
To drive the device from an external clock source, XTAL1 should be
driven while XTAL2 is left unconnected. However, minimum and
maximum high and low times specified in the data sheet must be
observed.
RESET
A reset is accomplished by holding the RST pin HIGH for at least
two machine cycles (24 oscillator periods in 12-clock and 12
oscillator periods in 6-clock mode), while the oscillator is running. To
insure a reliable power-up reset, the RST pin must be high long
enough to allow the oscillator time to start up (normally a few
milliseconds) plus two machine cycles, unless it has been set to
6-clock operation using a parallel programmer.
Clock Control Register (CKCON)
This device provides control of the 6-clock/12-clock mode by both
an SFR bit (bit X2 in register CKCON) and a Flash bit (bit FX2,
located in the Security Block). When X2 is 0, 12-clock mode is
activated. By setting this bit to 1, the system is switching to 6-clock
mode. Having this option implemented as SFR bit, it can be
accessed anytime and changed to either value. Changing X2 from 0
to 1 will result in executing user code at twice the speed, since all
system time intervals will be divided by 2. Changing back from
6-clock to 12-clock mode will slow down running code by a factor of
2.
The Flash clock control bit (FX2) activates the 6-clock mode when
programmed using a parallel programmer, superceding the X2 bit
(CKCON.0). Please also see Table 2 below.
LOW POWER MODES
Stop Clock Mode
The static design enables the clock speed to be reduced down to
0 MHz (stopped). When the oscillator is stopped, the RAM and
Special Function Registers retain their values. This mode allows
step-by-step utilization and permits reduced system power
consumption by lowering the clock frequency down to any value. For
lowest power consumption the Power Down mode is suggested.
Table 2.
FX2 clock mode bit
(can only be set by
parallel programmer)
X2 bit
(CKCON.0)
CPU clock mode
erased
0
12-clock mode
(default)
erased
1
6-clock mode
programmed
X
6-clock mode
2002 Jun 06
Idle Mode
In idle mode (see Table 3), the CPU puts itself to sleep while all of
the on-chip peripherals stay active. The instruction to invoke the idle
mode is the last instruction executed in the normal operating mode
before the idle mode is activated. The CPU contents, the on-chip
RAM, and all of the special function registers remain intact during
this mode. The idle mode can be terminated either by any enabled
interrupt (at which time the process is picked up at the interrupt
service routine and continued), or by a hardware reset which starts
the processor in the same manner as a power-on reset.
11
Philips Semiconductors
Preliminary data
80C51 8-bit Flash microcontroller family
P89C51X2/52X2/54X2/58X2
4K/8K/16K/32K Flash
executed after RETI will be the one following the instruction that put
the device into Power Down.
Power-Down Mode
To save even more power, a Power Down mode (see Table 3) can
be invoked by software. In this mode, the oscillator is stopped and
the instruction that invoked Power Down is the last instruction
executed. The on-chip RAM and Special Function Registers retain
their values down to 2.0 V and care must be taken to return VCC to
the minimum specified operating voltages before the Power Down
Mode is terminated.
Design Consideration
When the idle mode is terminated by a hardware reset, the device
normally resumes program execution from where it left off, up to two
machine cycles before the internal reset algorithm takes control.
On-chip hardware inhibits access to internal RAM in this event, but
access to the port pins is not inhibited. To eliminate the possibility of
an unexpected write when Idle is terminated by reset, the instruction
following the one that invokes Idle should not be one that writes to a
port pin or to external memory.
Either a hardware reset or external interrupt can be used to exit from
Power Down. Reset redefines all the SFRs but does not change the
on-chip RAM. An external interrupt allows both the SFRs and the
on-chip RAM to retain their values. WUPD (AUXR1.3–Wakeup from
Power Down) enables or disables the wakeup from power down with
external interrupt. Where:
ONCE Mode
The ONCE (“On-Circuit Emulation”) Mode facilitates testing and
debugging of systems without the device having to be removed from
the circuit. The ONCE Mode is invoked in the following way:
WUPD = 0: Disable
WUPD = 1: Enable
1. Pull ALE low while the device is in reset and PSEN is high;
To properly terminate Power Down, the reset or external interrupt
should not be executed before VCC is restored to its normal
operating level and must be held active long enough for the
oscillator to restart and stabilize (normally less than 10 ms).
2. Hold ALE low as RST is deactivated.
While the device is in ONCE Mode, the Port 0 pins go into a float
state, and the other port pins and ALE and PSEN are weakly pulled
high. The oscillator circuit remains active. While the device is in this
mode, an emulator or test CPU can be used to drive the circuit.
Normal operation is restored when a normal reset is applied.
To terminate Power Down with an external interrupt, INT0 or INT1
must be enabled and configured as level-sensitive. Holding the pin
low restarts the oscillator but bringing the pin back high completes
the exit. Once the interrupt is serviced, the next instruction to be
Table 3. External Pin Status During Idle and Power-Down Modes
PROGRAM MEMORY
ALE
PSEN
PORT 0
PORT 1
PORT 2
PORT 3
Idle
MODE
Internal
1
1
Data
Data
Data
Data
Idle
External
1
1
Float
Data
Address
Data
Power-down
Internal
0
0
Data
Data
Data
Data
Power-down
External
0
0
Float
Data
Data
Data
Mode 0 operation is the same for Timer 0 as for Timer 1. There are
two different GATE bits, one for Timer 1 (TMOD.7) and one for Timer
0 (TMOD.3).
TIMER 0 AND TIMER 1 OPERATION
Timer 0 and Timer 1
The “Timer” or “Counter” function is selected by control bits C/T in
the Special Function Register TMOD. These two Timer/Counters
have four operating modes, which are selected by bit-pairs (M1, M0)
in TMOD. Modes 0, 1, and 2 are the same for both Timers/Counters.
Mode 3 is different. The four operating modes are described in the
following text.
Mode 1
Mode 1 is the same as Mode 0, except that the Timer register is
being run with all 16 bits.
Mode 2
Mode 2 configures the Timer register as an 8-bit Counter (TLn) with
automatic reload, as shown in Figure 4. Overflow from TLn not only
sets TFn, but also reloads TLn with the contents of THn, which is
preset by software. The reload leaves THn unchanged.
Mode 0
Putting either Timer into Mode 0 makes it look like an 8048 Timer,
which is an 8-bit Counter with a divide-by-32 prescaler. Figure 2
shows the Mode 0 operation.
Mode 2 operation is the same for Timer 0 as for Timer 1.
In this mode, the Timer register is configured as a 13-bit register. As
the count rolls over from all 1s to all 0s, it sets the Timer interrupt
flag TFn. The counted input is enabled to the Timer when TRn = 1
and either GATE = 0 or INTn = 1. (Setting GATE = 1 allows the
Timer to be controlled by external input INTn, to facilitate pulse width
measurements). TRn is a control bit in the Special Function Register
TCON (Figure 3).
Mode 3
Timer 1 in Mode 3 simply holds its count. The effect is the same as
setting TR1 = 0.
Timer 0 in Mode 3 establishes TL0 and TH0 as two separate
counters. The logic for Mode 3 on Timer 0 is shown in Figure 5. TL0
uses the Timer 0 control bits: C/T, GATE, TR0, and TF0 as well as
pin INT0. TH0 is locked into a timer function (counting machine
cycles) and takes over the use of TR1 and TF1 from Timer 1. Thus,
TH0 now controls the “Timer 1” interrupt.
The 13-bit register consists of all 8 bits of THn and the lower 5 bits
of TLn. The upper 3 bits of TLn are indeterminate and should be
ignored. Setting the run flag (TRn) does not clear the registers.
2002 Jun 06
12
Philips Semiconductors
Preliminary data
80C51 8-bit Flash microcontroller family
P89C51X2/52X2/54X2/58X2
4K/8K/16K/32K Flash
Mode 3 is provided for applications requiring an extra 8-bit timer on
the counter. With Timer 0 in Mode 3, an 80C51 can look like it has
three Timer/Counters. When Timer 0 is in Mode 3, Timer 1 can be
TMOD
turned on and off by switching it out of and into its own Mode 3, or
can still be used by the serial port as a baud rate generator, or in
fact, in any application not requiring an interrupt.
Address = 89H
Reset Value = 00H
Not Bit Addressable
7
6
5
4
3
2
1
0
GATE
C/T
M1
M0
GATE
C/T
M1
M0
TIMER 1
BIT
TMOD.3/
TMOD.7
TMOD.2/
TMOD.6
SYMBOL
GATE
C/T
TIMER 0
FUNCTION
Gating control when set. Timer/Counter “n” is enabled only while “INTn” pin is high and
“TRn” control pin is set. when cleared Timer “n” is enabled whenever “TRn” control bit is set.
Timer or Counter Selector cleared for Timer operation (input from internal system clock.)
Set for Counter operation (input from “Tn” input pin).
M1
M0
OPERATING
0
0
8048 Timer: “TLn” serves as 5-bit prescaler.
0
1
16-bit Timer/Counter: “THn” and “TLn” are cascaded; there is no prescaler.
1
0
8-bit auto-reload Timer/Counter: “THn” holds a value which is to be reloaded
into “TLn” each time it overflows.
1
1
(Timer 0) TL0 is an 8-bit Timer/Counter controlled by the standard Timer 0 control bits.
TH0 is an 8-bit timer only controlled by Timer 1 control bits.
1
1
(Timer 1) Timer/Counter 1 stopped.
SU01580
Figure 1. Timer/Counter 0/1 Mode Control (TMOD) Register
÷ d*
OSC
C/T = 0
TLn
(5 Bits)
THn
(8 Bits)
TFn
Interrupt
C/T = 1
Control
Tn Pin
TRn
Timer n
Gate bit
INTn Pin
*d = 6 in 6-clock mode; d = 12 in 12-clock mode.
SU01618
Figure 2. Timer/Counter 0/1 Mode 0: 13-Bit Timer/Counter
2002 Jun 06
13
Philips Semiconductors
Preliminary data
80C51 8-bit Flash microcontroller family
P89C51X2/52X2/54X2/58X2
4K/8K/16K/32K Flash
TCON
Address = 88H
Reset Value = 00H
Bit Addressable
7
TF1
BIT
TCON.7
SYMBOL
TF1
TCON.6
TCON.5
TR1
TF0
TCON.4
TCON.3
TR0
IE1
TCON.2
IT1
TCON.1
IE0
TCON.0
IT0
6
5
4
3
2
1
0
TR1
TF0
TR0
IE1
IT1
IE0
IT0
FUNCTION
Timer 1 overflow flag. Set by hardware on Timer/Counter overflow.
Cleared by hardware when processor vectors to interrupt routine, or clearing the bit in software.
Timer 1 Run control bit. Set/cleared by software to turn Timer/Counter on/off.
Timer 0 overflow flag. Set by hardware on Timer/Counter overflow.
Cleared by hardware when processor vectors to interrupt routine, or by clearing the bit in software.
Timer 0 Run control bit. Set/cleared by software to turn Timer/Counter on/off.
Interrupt 1 Edge flag. Set by hardware when external interrupt edge detected.
Cleared when interrupt processed.
Interrupt 1 type control bit. Set/cleared by software to specify falling edge/low level triggered
external interrupts.
Interrupt 0 Edge flag. Set by hardware when external interrupt edge detected.
Cleared when interrupt processed.
Interrupt 0 Type control bit. Set/cleared by software to specify falling edge/low level
triggered external interrupts.
SU01516
Figure 3. Timer/Counter 0/1 Control (TCON) Register
÷ d*
OSC
C/T = 0
TLn
(8 Bits)
TFn
Interrupt
C/T = 1
Control
Tn Pin
Reload
TRn
Timer n
Gate bit
THn
(8 Bits)
INTn Pin
SU01619
*d = 6 in 6-clock mode; d = 12 in 12-clock mode.
Figure 4. Timer/Counter 0/1 Mode 2: 8-Bit Auto-Reload
2002 Jun 06
14
Philips Semiconductors
Preliminary data
80C51 8-bit Flash microcontroller family
P89C51X2/52X2/54X2/58X2
4K/8K/16K/32K Flash
÷ d*
OSC
C/T = 0
TL0
(8 Bits)
TF0
Interrupt
TH0
(8 Bits)
TF1
Interrupt
C/T = 1
Control
T0 Pin
TR0
Timer 0
Gate bit
INT0 Pin
OSC
÷ d*
Control
TR1
*d = 6 in 6-clock mode; d = 12 in 12-clock mode.
SU01620
Figure 5. Timer/Counter 0 Mode 3: Two 8-Bit Counters
Counter Enable) which is located in the T2MOD register (see
Figure 8). After reset, DCEN=0 which means Timer 2 will default to
counting up. If DCEN is set, Timer 2 can count up or down
depending on the value of the T2EX pin.
TIMER 2 OPERATION
Timer 2
Timer 2 is a 16-bit Timer/Counter which can operate as either an
event timer or an event counter, as selected by C/T2 in the special
function register T2CON (see Figure 6). Timer 2 has three operating
modes: Capture, Auto-reload (up or down counting), and Baud Rate
Generator, which are selected by bits in the T2CON as shown in
Table 4.
Figure 9 shows Timer 2 which will count up automatically since
DCEN=0. In this mode there are two options selected by bit EXEN2
in T2CON register. If EXEN2=0, then Timer 2 counts up to 0FFFFH
and sets the TF2 (Overflow Flag) bit upon overflow. This causes the
Timer 2 registers to be reloaded with the 16-bit value in RCAP2L
and RCAP2H. The values in RCAP2L and RCAP2H are preset by
software.
Capture Mode
In the capture mode there are two options which are selected by bit
EXEN2 in T2CON. If EXEN2=0, then timer 2 is a 16-bit timer or
counter (as selected by C/T2 in T2CON) which, upon overflowing,
sets bit TF2, the timer 2 overflow bit. This bit can be used to
generate an interrupt (by enabling the Timer 2 interrupt bit in the
IE register). If EXEN2=1, Timer 2 operates as described above, but
with the added feature that a 1-to-0 transition at external input T2EX
causes the current value in the Timer 2 registers, TL2 and TH2, to
be captured into registers RCAP2L and RCAP2H, respectively. In
addition, the transition at T2EX causes bit EXF2 in T2CON to be
set, and EXF2 (like TF2) can generate an interrupt (which vectors to
the same location as Timer 2 overflow interrupt. The Timer 2
interrupt service routine can interrogate TF2 and EXF2 to determine
which event caused the interrupt). The capture mode is illustrated in
Figure 7 (There is no reload value for TL2 and TH2 in this mode.
Even when a capture event occurs from T2EX, the counter keeps on
counting T2EX pin transitions or osc/12 (12-clock Mode) or osc/6
(6-clock Mode) pulses).
If EXEN2=1, then a 16-bit reload can be triggered either by an
overflow or by a 1-to-0 transition at input T2EX. This transition also
sets the EXF2 bit. The Timer 2 interrupt, if enabled, can be
generated when either TF2 or EXF2 are 1.
In Figure 10 DCEN=1 which enables Timer 2 to count up or down.
This mode allows pin T2EX to control the direction of count. When a
logic 1 is applied at pin T2EX, Timer 2 will count up. Timer 2 will
overflow at 0FFFFH and set the TF2 flag, which can then generate
an interrupt, if the interrupt is enabled. This timer overflow also
causes the 16-bit value in RCAP2L and RCAP2H to be reloaded
into the timer registers TL2 and TH2.
A logic 0 applied to pin T2EX causes Timer 2 to count down. The
timer will underflow when TL2 and TH2 become equal to the value
stored in RCAP2L and RCAP2H. A Timer 2 underflow sets the TF2
flag and causes 0FFFFH to be reloaded into the timer registers TL2
and TH2.
The external flag EXF2 toggles when Timer 2 underflows or
overflows. This EXF2 bit can be used as a 17th bit of resolution if
needed. The EXF2 flag does not generate an interrupt in this mode
of operation.
Auto-Reload Mode (Up or Down Counter)
In the 16-bit auto-reload mode, Timer 2 can be configured as either
a timer or counter (C/T2 in T2CON), then programmed to count up
or down. The counting direction is determined by bit DCEN (Down
2002 Jun 06
15
Philips Semiconductors
Preliminary data
80C51 8-bit Flash microcontroller family
P89C51X2/52X2/54X2/58X2
4K/8K/16K/32K Flash
Table 4. Timer 2 Operating Modes
RCLK + TCLK
CP/RL2
TR2
0
0
1
16-bit Auto-reload
0
1
1
16-bit Capture
1
X
1
Baud rate generator
X
X
0
(off)
T2CON
MODE
Address = C8H
Bit Addressable
Reset Value = 00H
7
TF2
6
5
4
3
2
1
0
EXF2
RCLK
TCLK
EXEN2
TR2
C/T2
CP/RL2
Symbol
Position
Name and Significance
TF2
T2CON.7
EXF2
T2CON.6
RCLK
T2CON.5
TCLK
T2CON.4
EXEN2
T2CON.3
TR2
C/T2
T2CON.2
T2CON.1
CP/RL2
T2CON.0
Timer 2 overflow flag set by a Timer 2 overflow and must be cleared by software. TF2 will not be set
when either RCLK or TCLK = 1.
Timer 2 external flag set when either a capture or reload is caused by a negative transition on T2EX and
EXEN2 = 1. When Timer 2 interrupt is enabled, EXF2 = 1 will cause the CPU to vector to the Timer 2
interrupt routine. EXF2 must be cleared by software. EXF2 does not cause an interrupt in up/down
counter mode (DCEN = 1).
Receive clock flag. When set, causes the serial port to use Timer 2 overflow pulses for its receive clock
in modes 1 and 3. RCLK = 0 causes Timer 1 overflow to be used for the receive clock.
Transmit clock flag. When set, causes the serial port to use Timer 2 overflow pulses for its transmit clock
in modes 1 and 3. TCLK = 0 causes Timer 1 overflows to be used for the transmit clock.
Timer 2 external enable flag. When set, allows a capture or reload to occur as a result of a negative
transition on T2EX if Timer 2 is not being used to clock the serial port. EXEN2 = 0 causes Timer 2 to
ignore events at T2EX.
Start/stop control for Timer 2. A logic 1 starts the timer.
Timer or counter select. (Timer 2)
0 = Internal timer (OSC/12 in 12-clock mode or OSC/6 in 6-clock mode)
1 = External event counter (falling edge triggered).
Capture/Reload flag. When set, captures will occur on negative transitions at T2EX if EXEN2 = 1. When
cleared, auto-reloads will occur either with Timer 2 overflows or negative transitions at T2EX when
EXEN2 = 1. When either RCLK = 1 or TCLK = 1, this bit is ignored and the timer is forced to auto-reload
on Timer 2 overflow.
SU01621
Figure 6. Timer/Counter 2 (T2CON) Control Register
2002 Jun 06
16
Philips Semiconductors
Preliminary data
80C51 8-bit Flash microcontroller family
P89C51X2/52X2/54X2/58X2
4K/8K/16K/32K Flash
÷ n*
OSC
C/T2 = 0
TL2
(8 bits)
TH2
(8 bits)
TF2
C/T2 = 1
T2 Pin
Control
TR2
Capture
Transition
Detector
Timer 2
Interrupt
RCAP2L
RCAP2H
T2EX Pin
EXF2
Control
EXEN2
SU01622
*n = 6 in 6-clock mode; n = 12 in 12-clock mode.
Figure 7. Timer 2 in Capture Mode
T2MOD
Address = 0C9H
Reset Value = XXXX XX00B
Not Bit Addressable
Symbol
Position
—
*
7
6
5
4
3
2
1
0
—
—
—
—
—
—
T2OE
DCEN
Function
Not implemented, reserved for future use.*
T2OE
T2MOD.1
DCEN
T2MOD.0
Timer 2 Output Enable bit.
Down Count Enable bit. When set, this allows Timer 2 to be configured as an up/down
counter.
User software should not write 1s to reserved bits. These bits may be used in future 8051 family products to invoke new features.
In that case, the reset or inactive value of the new bit will be 0, and its active value will be 1. The value read from a reserved bit is
indeterminate.
SU01519
Figure 8. Timer 2 Mode (T2MOD) Control Register
2002 Jun 06
17
Philips Semiconductors
Preliminary data
80C51 8-bit Flash microcontroller family
P89C51X2/52X2/54X2/58X2
4K/8K/16K/32K Flash
÷ n*
OSC
C/T2 = 0
TL2
(8-BITS)
TH2
(8-BITS)
C/T2 = 1
T2 Pin
CONTROL
TR2
RELOAD
TRANSITION
DETECTOR
RCAP2L
RCAP2H
TF2
TIMER 2
INTERRUPT
T2EX PIN
EXF2
CONTROL
*n = 6 in 6-clock mode; n = 12 in 12-clock mode.
SU01623
EXEN2
Figure 9. Timer 2 in Auto-Reload Mode (DCEN = 0)
(DOWN COUNTING RELOAD VALUE)
FFH
FFH
TOGGLE
EXF2
÷ n*
OSC
C/T2 = 0
OVERFLOW
TL2
TH2
TF2
INTERRUPT
C/T2 = 1
T2 Pin
CONTROL
TR2
COUNT
DIRECTION
1 = UP
0 = DOWN
RCAP2L
RCAP2H
*n = 6 in 6-clock mode; n = 12 in 12-clock mode.
(UP COUNTING RELOAD VALUE)
Figure 10. Timer 2 Auto Reload Mode (DCEN = 1)
2002 Jun 06
18
T2EX PIN
SU01624
Philips Semiconductors
Preliminary data
80C51 8-bit Flash microcontroller family
P89C51X2/52X2/54X2/58X2
4K/8K/16K/32K Flash
Timer 1
Overflow
n = 1 in 6-clock mode
n = 2 in 12-clock mode.
÷2
OSC
“0”
÷n
“1”
C/T2 = 0
SMOD
TL2
(8 bits)
“1”
TH2
(8 bits)
“0”
RCLK
C/T2 = 1
T2 Pin
Control
÷ 16
“1”
TR2
Reload
Transition
Detector
RCAP2L
T2EX Pin
EXF2
RCAP2H
RX Clock
“0”
TCLK
÷ 16
TX Clock
Timer 2
Interrupt
Control
EXEN2
Note availability of additional external interrupt.
SU01625
Figure 11. Timer 2 in Baud Rate Generator Mode
Modes 1 and 3 Baud Rates =
Oscillator Frequency
[n [65536 * (RCAP2H, RCAP2L)]]
Baud Rate Generator Mode
Bits TCLK and/or RCLK in T2CON (Table 4) allow the serial port
transmit and receive baud rates to be derived from either Timer 1 or
Timer 2. When TCLK= 0, Timer 1 is used as the serial port transmit
baud rate generator. When TCLK= 1, Timer 2 is used as the serial
port transmit baud rate generator. RCLK has the same effect for the
serial port receive baud rate. With these two bits, the serial port can
have different receive and transmit baud rates – one generated by
Timer 1, the other by Timer 2.
Where:
n = 16 in 6-clock mode, 32 in 12-clock mode.
(RCAP2H, RCAP2L)= The content of RCAP2H and RCAP2L
taken as a 16-bit unsigned integer.
The Timer 2 as a baud rate generator mode shown in Figure 11 is
valid only if RCLK and/or TCLK = 1 in T2CON register. Note that a
rollover in TH2 does not set TF2, and will not generate an interrupt.
Thus, the Timer 2 interrupt does not have to be disabled when
Timer 2 is in the baud rate generator mode. Also if the EXEN2
(T2 external enable flag) is set, a 1-to-0 transition in T2EX
(Timer/counter 2 trigger input) will set EXF2 (T2 external flag) but
will not cause a reload from (RCAP2H, RCAP2L) to (TH2,TL2).
Therefore when Timer 2 is in use as a baud rate generator, T2EX
can be used as an additional external interrupt, if needed.
Figure 11 shows the Timer 2 in baud rate generation mode. The
baud rate generation mode is like the auto-reload mode, in that a
rollover in TH2 causes the Timer 2 registers to be reloaded with the
16-bit value in registers RCAP2H and RCAP2L, which are preset by
software.
The baud rates in modes 1 and 3 are determined by Timer 2’s
overflow rate given below:
Modes 1 and 3 Baud Rates + Timer 2 Overflow Rate
16
When Timer 2 is in the baud rate generator mode, one should not try
to read or write TH2 and TL2. As a baud rate generator, Timer 2 is
incremented every state time (osc/2) or asynchronously from pin T2;
under these conditions, a read or write of TH2 or TL2 may not be
accurate. The RCAP2 registers may be read, but should not be
written to, because a write might overlap a reload and cause write
and/or reload errors. The timer should be turned off (clear TR2)
before accessing the Timer 2 or RCAP2 registers.
The timer can be configured for either “timer” or “counter” operation.
In many applications, it is configured for “timer” operation (C/T2=0).
Timer operation is different for Timer 2 when it is being used as a
baud rate generator.
Usually, as a timer it would increment every machine cycle (i.e., 1/6
the oscillator frequency in 6-clock mode or 1/12 the oscillator
frequency in 12-clock mode). As a baud rate generator, it
increments at the oscillator frequency in 6-clock mode or at 1/2 the
oscillator frequency in 12-clock mode. Thus the baud rate formula is
as follows:
2002 Jun 06
Table 5 shows commonly used baud rates and how they can be
obtained from Timer 2.
19
Philips Semiconductors
Preliminary data
80C51 8-bit Flash microcontroller family
P89C51X2/52X2/54X2/58X2
4K/8K/16K/32K Flash
Table 5.
Timer 2 Generated Commonly Used
Baud Rates
Baud Rate
Timer/Counter 2 Set-up
Except for the baud rate generator mode, the values given for
T2CON do not include the setting of the TR2 bit. Therefore, bit TR2
must be set, separately, to turn the timer on. See Table 6 for set-up
of Timer 2 as a timer. Also see Table 7 for set-up of Timer 2 as a
counter.
Timer 2
12-clk
mode
6-clk
mode
Osc Freq
375 K
9.6 K
4.8 K
2.4 K
1.2 K
300
110
300
110
750 K
19.2 K
9.6 K
4.8 K
2.4 K
600
220
600
220
12 MHz
12 MHz
12 MHz
12 MHz
12 MHz
12 MHz
12 MHz
6 MHz
6 MHz
RCAP2H
RCAP2L
FF
FF
FF
FF
FE
FB
F2
FD
F9
FF
D9
B2
64
C8
1E
AF
8F
57
Table 6. Timer 2 as a Timer
T2CON
Summary Of Baud Rate Equations
Timer 2 is in baud rate generating mode. If Timer 2 is being clocked
through pin T2(P1.0) the baud rate is:
Baud Rate + Timer 2 Overflow Rate
16
MODE
INTERNAL
CONTROL
(Note 1)
EXTERNAL
CONTROL
(Note 2)
16-bit Auto-Reload
00H
08H
16-bit Capture
01H
09H
Baud rate generator receive
and transmit same baud rate
34H
36H
Receive only
24H
26H
Transmit only
14H
16H
Table 7. Timer 2 as a Counter
If Timer 2 is being clocked internally, the baud rate is:
Baud Rate +
[n
TMOD
f OSC
[65536 * (RCAP2H, RCAP2L)]]
MODE
Where:
n = 16 in 6-clock mode, 32 in 12-clock mode.
INTERNAL
CONTROL
(Note 1)
EXTERNAL
CONTROL
(Note 2)
16-bit
02H
0AH
Auto-Reload
03H
0BH
fOSC= Oscillator Frequency
NOTES:
1. Capture/reload occurs only on timer/counter overflow.
2. Capture/reload occurs on timer/counter overflow and a 1-to-0
transition on T2EX (P1.1) pin except when Timer 2 is used in the
baud rate generator mode.
To obtain the reload value for RCAP2H and RCAP2L, the above
equation can be rewritten as:
RCAP2H, RCAP2L + 65536 *
2002 Jun 06
ǒ
n
Ǔ
f OSC
Baud Rate
20
Philips Semiconductors
Preliminary data
80C51 8-bit Flash microcontroller family
P89C51X2/52X2/54X2/58X2
4K/8K/16K/32K Flash
The slaves that weren’t being addressed leave their SM2s set and
go on about their business, ignoring the coming data bytes.
FULL-DUPLEX ENHANCED UART
Standard UART operation
SM2 has no effect in Mode 0, and in Mode 1 can be used to check
the validity of the stop bit. In a Mode 1 reception, if SM2 = 1, the
receive interrupt will not be activated unless a valid stop bit is
received.
The serial port is full duplex, meaning it can transmit and receive
simultaneously. It is also receive-buffered, meaning it can
commence reception of a second byte before a previously received
byte has been read from the register. (However, if the first byte still
hasn’t been read by the time reception of the second byte is
complete, one of the bytes will be lost.) The serial port receive and
transmit registers are both accessed at Special Function Register
SBUF. Writing to SBUF loads the transmit register, and reading
SBUF accesses a physically separate receive register.
Serial Port Control Register
The serial port control and status register is the Special Function
Register SCON, shown in Figure 12. This register contains not only
the mode selection bits, but also the 9th data bit for transmit and
receive (TB8 and RB8), and the serial port interrupt bits (TI and RI).
The serial port can operate in 4 modes:
Mode 0:
Serial data enters and exits through RxD. TxD outputs
the shift clock. 8 bits are transmitted/received (LSB first).
The baud rate is fixed at 1/12 the oscillator frequency (in
12-clock mode) or 1/6 the oscillator frequency (in 6-clock
mode).
Mode 1:
10 bits are transmitted (through TxD) or received
(through RxD): a start bit (0), 8 data bits (LSB first), and
a stop bit (1). On receive, the stop bit goes into RB8 in
Special Function Register SCON. The baud rate is
variable.
Mode 2:
Mode 3:
Baud Rates
The baud rate in Mode 0 is fixed: Mode 0 Baud Rate = Oscillator
Frequency / 12 (in 12-clock mode) or / 6 (in 6-clock mode). The
baud rate in Mode 2 depends on the value of bit SMOD in Special
Function Register PCON. If SMOD = 0 (which is the value on reset),
and the port pins in 12-clock mode, the baud rate is 1/64 the
oscillator frequency. If SMOD = 1, the baud rate is 1/32 the oscillator
frequency. In 6-clock mode, the baud rate is 1/32 or 1/16 the
oscillator frequency, respectively.
Mode 2 Baud Rate =
2 SMOD
n
11 bits are transmitted (through TxD) or received
(through RxD): start bit (0), 8 data bits (LSB first), a
programmable 9th data bit, and a stop bit (1). On
Transmit, the 9th data bit (TB8 in SCON) can be
assigned the value of 0 or 1. Or, for example, the parity
bit (P, in the PSW) could be moved into TB8. On receive,
the 9th data bit goes into RB8 in Special Function
Register SCON, while the stop bit is ignored. The baud
rate is programmable to either 1/32 or 1/64 the oscillator
frequency (in 12-clock mode) or 1/16 or 1/32 the
oscillator frequency (in 6-clock mode).
Where:
n = 64 in 12-clock mode, 32 in 6-clock mode
The baud rates in Modes 1 and 3 are determined by the Timer 1 or
Timer 2 overflow rate.
Using Timer 1 to Generate Baud Rates
When Timer 1 is used as the baud rate generator (T2CON.RCLK
= 0, T2CON.TCLK = 0), the baud rates in Modes 1 and 3 are
determined by the Timer 1 overflow rate and the value of SMOD as
follows:
11 bits are transmitted (through TxD) or received
(through RxD): a start bit (0), 8 data bits (LSB first), a
programmable 9th data bit, and a stop bit (1). In fact,
Mode 3 is the same as Mode 2 in all respects except
baud rate. The baud rate in Mode 3 is variable.
Mode 1, 3 Baud Rate =
2 SMOD
n
(Timer 1 Overflow Rate)
Where:
In all four modes, transmission is initiated by any instruction that
uses SBUF as a destination register. Reception is initiated in Mode 0
by the condition RI = 0 and REN = 1. Reception is initiated in the
other modes by the incoming start bit if REN = 1.
n = 32 in 12-clock mode, 16 in 6-clock mode
The Timer 1 interrupt should be disabled in this application. The
Timer itself can be configured for either “timer” or “counter”
operation, and in any of its 3 running modes. In the most typical
applications, it is configured for “timer” operation, in the auto-reload
mode (high nibble of TMOD = 0010B). In that case the baud rate is
given by the formula:
Multiprocessor Communications
Modes 2 and 3 have a special provision for multiprocessor
communications. In these modes, 9 data bits are received. The 9th
one goes into RB8. Then comes a stop bit. The port can be
programmed such that when the stop bit is received, the serial port
interrupt will be activated only if RB8 = 1. This feature is enabled by
setting bit SM2 in SCON. A way to use this feature in multiprocessor
systems is as follows:
Mode 1, 3 Baud Rate =
2 SMOD
n
Oscillator Frequency
12 [256–(TH1)]
Where:
When the master processor wants to transmit a block of data to one
of several slaves, it first sends out an address byte which identifies
the target slave. An address byte differs from a data byte in that the
9th bit is 1 in an address byte and 0 in a data byte. With SM2 = 1, no
slave will be interrupted by a data byte. An address byte, however,
will interrupt all slaves, so that each slave can examine the received
byte and see if it is being addressed. The addressed slave will clear
its SM2 bit and prepare to receive the data bytes that will be coming.
2002 Jun 06
(Oscillator Frequency)
n = 32 in 12-clock mode, 16 in 6-clock mode
One can achieve very low baud rates with Timer 1 by leaving the
Timer 1 interrupt enabled, and configuring the Timer to run as a
16-bit timer (high nibble of TMOD = 0001B), and using the Timer 1
interrupt to do a 16-bit software reload. Figure 13 lists various
commonly used baud rates and how they can be obtained from
Timer 1.
21
Philips Semiconductors
Preliminary data
80C51 8-bit Flash microcontroller family
P89C51X2/52X2/54X2/58X2
4K/8K/16K/32K Flash
SCON
Address = 98H
Bit Addressable
Reset Value = 00H
7
6
5
4
3
2
1
0
SM0
SM1
SM2
REN
TB8
RB8
TI
RI
Where SM0, SM1 specify the serial port mode, as follows:
SM0
0
0
1
1
SM1
0
1
0
1
Mode
0
1
2
3
Description
shift register
8-bit UART
9-bit UART
9-bit UART
Baud Rate
fOSC/12 (12-clock mode) or fOSC/6 (6-clock mode)
variable
fOSC/64 or fOSC/32 (12-clock mode) or fOSC/32 or fOSC/16 (6-clock mode)
variable
SM2
Enables the multiprocessor communication feature in Modes 2 and 3. In Mode 2 or 3, if SM2 is set to 1, then Rl will not be
activated if the received 9th data bit (RB8) is 0. In Mode 1, if SM2=1 then RI will not be activated if a valid stop bit was not
received. In Mode 0, SM2 should be 0.
REN
Enables serial reception. Set by software to enable reception. Clear by software to disable reception.
TB8
The 9th data bit that will be transmitted in Modes 2 and 3. Set or clear by software as desired.
RB8
In Modes 2 and 3, is the 9th data bit that was received. In Mode 1, it SM2=0, RB8 is the stop bit that was received. In Mode 0,
RB8 is not used.
TI
Transmit interrupt flag. Set by hardware at the end of the 8th bit time in Mode 0, or at the beginning of the stop bit in the other
modes, in any serial transmission. Must be cleared by software.
RI
Receive interrupt flag. Set by hardware at the end of the 8th bit time in Mode 0, or halfway through the stop bit time in the other
modes, in any serial reception (except see SM2). Must be cleared by software.
SU01626
Figure 12. Serial Port Control (SCON) Register
Timer 1
Baud Rate
Mode
12-clock mode
6-clock mode
Mode 0 Max
Mode 2 Max
Mode 1, 3 Max
Mode 1, 3
1.67 MHz
625 k
104.2 k
19.2 k
9.6 k
4.8 k
2.4 k
1.2 k
137.5
110
110
3.34 MHz
1250 k
208.4 k
38.4 k
19.2 k
9.6 k
4.8 k
2.4 k
275
220
220
fOSC
SMOD
20 MHz
20 MHz
20 MHz
11.059 MHz
11.059 MHz
11.059 MHz
11.059 MHz
11.059 MHz
11.986 MHz
6 MHz
12 MHz
X
1
1
1
0
0
0
0
0
0
0
C/T
Mode
Reload Value
X
X
0
0
0
0
0
0
0
0
0
X
X
2
2
2
2
2
2
2
2
1
X
X
FFH
FDH
FDH
FAH
F4H
E8H
1DH
72H
FEEBH
Figure 13. Timer 1 Generated Commonly Used Baud Rates
More About Mode 0
Serial data enters and exits through RxD. TxD outputs the shift
clock. 8 bits are transmitted/received: 8 data bits (LSB first). The
baud rate is fixed at 1/12 the oscillator frequency (12-clock mode) or
1/6 the oscillator frequency (6-clock mode).
S6P2 of every machine cycle in which SEND is active, the contents
of the transmit shift are shifted to the right one position.
As data bits shift out to the right, zeros come in from the left. When
the MSB of the data byte is at the output position of the shift register,
then the 1 that was initially loaded into the 9th position, is just to the
left of the MSB, and all positions to the left of that contain zeros.
This condition flags the TX Control block to do one last shift and
then deactivate SEND and set T1. Both of these actions occur at
S1P1 of the 10th machine cycle after “write to SBUF.”
Figure 14 shows a simplified functional diagram of the serial port in
Mode 0, and associated timing.
Transmission is initiated by any instruction that uses SBUF as a
destination register. The “write to SBUF” signal at S6P2 also loads a
1 into the 9th position of the transmit shift register and tells the TX
Control block to commence a transmission. The internal timing is
such that one full machine cycle will elapse between “write to SBUF”
and activation of SEND.
Reception is initiated by the condition REN = 1 and R1 = 0. At S6P2
of the next machine cycle, the RX Control unit writes the bits
11111110 to the receive shift register, and in the next clock phase
activates RECEIVE.
RECEIVE enable SHIFT CLOCK to the alternate output function line
of P3.1. SHIFT CLOCK makes transitions at S3P1 and S6P1 of
every machine cycle. At S6P2 of every machine cycle in which
RECEIVE is active, the contents of the receive shift register are
SEND enables the output of the shift register to the alternate output
function line of P3.0 and also enable SHIFT CLOCK to the alternate
output function line of P3.1. SHIFT CLOCK is low during S3, S4, and
S5 of every machine cycle, and high during S6, S1, and S2. At
2002 Jun 06
22
Philips Semiconductors
Preliminary data
80C51 8-bit Flash microcontroller family
P89C51X2/52X2/54X2/58X2
4K/8K/16K/32K Flash
shifted to the left one position. The value that comes in from the right
is the value that was sampled at the P3.0 pin at S5P2 of the same
machine cycle.
whether the above conditions are met or not, the unit goes back to
looking for a 1-to-0 transition in RxD.
More About Modes 2 and 3
Eleven bits are transmitted (through TxD), or received (through
RxD): a start bit (0), 8 data bits (LSB first), a programmable 9th data
bit, and a stop bit (1). On transmit, the 9th data bit (TB8) can be
assigned the value of 0 or 1. On receive, the 9the data bit goes into
RB8 in SCON. The baud rate is programmable to either 1/32 or 1/64
(12-clock mode) or 1/16 or 1/32 the oscillator frequency (6-clock
mode) the oscillator frequency in Mode 2. Mode 3 may have a
variable baud rate generated from Timer 1 or Timer 2.
As data bits come in from the right, 1s shift out to the left. When the
0 that was initially loaded into the rightmost position arrives at the
leftmost position in the shift register, it flags the RX Control block to
do one last shift and load SBUF. At S1P1 of the 10th machine cycle
after the write to SCON that cleared RI, RECEIVE is cleared as RI is
set.
More About Mode 1
Ten bits are transmitted (through TxD), or received (through RxD): a
start bit (0), 8 data bits (LSB first), and a stop bit (1). On receive, the
stop bit goes into RB8 in SCON. In the 80C51 the baud rate is
determined by the Timer 1 or Timer 2 overflow rate.
Figures 16 and 17 show a functional diagram of the serial port in
Modes 2 and 3. The receive portion is exactly the same as in Mode
1. The transmit portion differs from Mode 1 only in the 9th bit of the
transmit shift register.
Figure 15 shows a simplified functional diagram of the serial port in
Mode 1, and associated timings for transmit receive.
Transmission is initiated by any instruction that uses SBUF as a
destination register. The “write to SBUF” signal also loads TB8 into
the 9th bit position of the transmit shift register and flags the TX
Control unit that a transmission is requested. Transmission
commences at S1P1 of the machine cycle following the next rollover
in the divide-by-16 counter. (Thus, the bit times are synchronized to
the divide-by-16 counter, not to the “write to SBUF” signal.)
Transmission is initiated by any instruction that uses SBUF as a
destination register. The “write to SBUF” signal also loads a 1 into
the 9th bit position of the transmit shift register and flags the TX
Control unit that a transmission is requested. Transmission actually
commences at S1P1 of the machine cycle following the next rollover
in the divide-by-16 counter. (Thus, the bit times are synchronized to
the divide-by-16 counter, not to the “write to SBUF” signal.)
The transmission begins with activation of SEND, which puts the
start bit at TxD. One bit time later, DATA is activated, which enables
the output bit of the transmit shift register to TxD. The first shift pulse
occurs one bit time after that. The first shift clocks a 1 (the stop bit)
into the 9th bit position of the shift register. Thereafter, only zeros
are clocked in. Thus, as data bits shift out to the right, zeros are
clocked in from the left. When TB8 is at the output position of the
shift register, then the stop bit is just to the left of TB8, and all
positions to the left of that contain zeros. This condition flags the TX
Control unit to do one last shift and then deactivate SEND and set
TI. This occurs at the 11th divide-by-16 rollover after “write to SUBF.”
The transmission begins with activation of SEND which puts the
start bit at TxD. One bit time later, DATA is activated, which enables
the output bit of the transmit shift register to TxD. The first shift pulse
occurs one bit time after that.
As data bits shift out to the right, zeros are clocked in from the left.
When the MSB of the data byte is at the output position of the shift
register, then the 1 that was initially loaded into the 9th position is
just to the left of the MSB, and all positions to the left of that contain
zeros. This condition flags the TX Control unit to do one last shift
and then deactivate SEND and set TI. This occurs at the 10th
divide-by-16 rollover after “write to SBUF.”
Reception is initiated by a detected 1-to-0 transition at RxD. For this
purpose RxD is sampled at a rate of 16 times whatever baud rate
has been established. When a transition is detected, the
divide-by-16 counter is immediately reset, and 1FFH is written to the
input shift register.
Reception is initiated by a detected 1-to-0 transition at RxD. For this
purpose RxD is sampled at a rate of 16 times whatever baud rate
has been established. When a transition is detected, the
divide-by-16 counter is immediately reset, and 1FFH is written into
the input shift register. Resetting the divide-by-16 counter aligns its
rollovers with the boundaries of the incoming bit times.
At the 7th, 8th, and 9th counter states of each bit time, the bit
detector samples the value of R-D. The value accepted is the value
that was seen in at least 2 of the 3 samples. If the value accepted
during the first bit time is not 0, the receive circuits are reset and the
unit goes back to looking for another 1-to-0 transition. If the start bit
proves valid, it is shifted into the input shift register, and reception of
the rest of the frame will proceed.
The 16 states of the counter divide each bit time into 16ths. At the
7th, 8th, and 9th counter states of each bit time, the bit detector
samples the value of RxD. The value accepted is the value that was
seen in at least 2 of the 3 samples. This is done for noise rejection.
If the value accepted during the first bit time is not 0, the receive
circuits are reset and the unit goes back to looking for another 1-to-0
transition. This is to provide rejection of false start bits. If the start bit
proves valid, it is shifted into the input shift register, and reception of
the rest of the frame will proceed.
As data bits come in from the right, 1s shift out to the left. When the
start bit arrives at the leftmost position in the shift register (which in
Modes 2 and 3 is a 9-bit register), it flags the RX Control block to do
one last shift, load SBUF and RB8, and set RI.
The signal to load SBUF and RB8, and to set RI, will be generated
if, and only if, the following conditions are met at the time the final
shift pulse is generated.
1. RI = 0, and
2. Either SM2 = 0, or the received 9th data bit = 1.
As data bits come in from the right, 1s shift out to the left. When the
start bit arrives at the leftmost position in the shift register (which in
mode 1 is a 9-bit register), it flags the RX Control block to do one
last shift, load SBUF and RB8, and set RI. The signal to load SBUF
and RB8, and to set RI, will be generated if, and only if, the following
conditions are met at the time the final shift pulse is generated.:
1. R1 = 0, and
2. Either SM2 = 0, or the received stop bit = 1.
If either of these conditions is not met, the received frame is
irretrievably lost, and RI is not set. If both conditions are met, the
received 9th data bit goes into RB8, and the first 8 data bits go into
SBUF. One bit time later, whether the above conditions were met or
not, the unit goes back to looking for a 1-to-0 transition at the RxD
input.
If either of these two conditions is not met, the received frame is
irretrievably lost. If both conditions are met, the stop bit goes into
RB8, the 8 data bits go into SBUF, and RI is activated. At this time,
2002 Jun 06
23
Philips Semiconductors
Preliminary data
80C51 8-bit Flash microcontroller family
P89C51X2/52X2/54X2/58X2
4K/8K/16K/32K Flash
80C51 Internal Bus
Write
to
SBUF
S
D
Q
RxD
P3.0 Alt
Output
Function
SBUF
CL
Zero Detector
Start
Shift
TX Control
S6
T1
TX Clock
Send
Serial
Port
Interrupt
R1
RX Clock
Receive
RX Control
REN
RI
Start
1
1
1
TxD
P3.1 Alt
Output
Function
Shift
Clock
Shift
1
1
1
1
0
MSB
LSB
RxD
P3.0 Alt
Input
Function
Input Shift Register
Shift
Load
SBUF
LSB
MSB
SBUF
Read
SBUF
80C51 Internal Bus
S4 . .
S1 . . . . S6 S1 . . . . S6 S1 . . . . S6 S1 . . . . S6 S1 . . . . S6 S1 . . . . S6 S1 . . . . S6 S1 . . . . S6 S1 . . . . S6 S1 . . . . S6 S1
ALE
Write to SBUF
S6P2
Send
Shift
Transmit
RxD (Data Out)
D0
D1
D2
D3
D4
D5
D6
D7
TxD (Shift Clock)
S3P1
TI
S6P1
Write to SCON (Clear RI)
RI
Receive
Shift
RxD (Data In)
Receive
D0
D1
D2
D3
D4
D5
D6
D7
S5P2
TxD (Shift Clock)
SU00539
Figure 14. Serial Port Mode 0
2002 Jun 06
24
Philips Semiconductors
Preliminary data
80C51 8-bit Flash microcontroller family
P89C51X2/52X2/54X2/58X2
4K/8K/16K/32K Flash
Timer 1
Overflow
80C51 Internal Bus
TB8
÷2
SMOD = 0
SMOD = 1
Write
to
SBUF
S
D
Q
SBUF
TxD
CL
Zero Detector
Start
Data
Shift
TX Control
÷ 16
T1
Send
RX Clock RI
Load
SBUF
TX Clock
Serial
Port
Interrupt
÷ 16
Sample
RX Control
1-to-0
Transition
Detector
Shift
Start
1FFH
Bit Detector
Input Shift Register
(9 Bits)
Shift
RxD
Load
SBUF
SBUF
Read
SBUF
80C51 Internal Bus
TX
Clock
Write to SBUF
Send
Data
S1P1
Transmit
Shift
TxD
Start Bit
D0
D1
D2
D3
D4
D5
D6
D7
Stop Bit
D0
D1
D2
D3
D4
D5
D6
D7
Stop Bit
TI
÷ 16 Reset
RX
Clock
RxD
Bit Detector
Sample Times
Start
Bit
Receive
Shift
RI
SU00540
Figure 15. Serial Port Mode 1
2002 Jun 06
25
Philips Semiconductors
Preliminary data
80C51 8-bit Flash microcontroller family
P89C51X2/52X2/54X2/58X2
4K/8K/16K/32K Flash
80C51 Internal Bus
TB8
Write
to
SBUF
S
D
Phase 2 Clock
(1/2 fOSC in
12-clock mode;
fOSC in 6-clock
mode)
Q
SBUF
TxD
CL
Zero Detector
Mode 2
Start
÷ 16
SMOD = 1
Stop Bit
Gen.
TX Control
TX Clock
Shift
Data
T1
Send
R1
Load
SBUF
Serial
Port
Interrupt
÷2
SMOD = 0
(SMOD is
PCON.7)
÷ 16
RX Clock
Sample
RX Control
1-to-0
Transition
Detector
Shift
Start
1FFH
Bit Detector
Input Shift Register
(9 Bits)
Shift
RxD
Load
SBUF
SBUF
Read
SBUF
80C51 Internal Bus
TX
Clock
Write to SBUF
Send
Data
S1P1
Transmit
Shift
TxD
Start Bit
D0
D1
D2
D3
D4
D5
D6
D7
TB8
D0
D1
D2
D3
D4
D5
D6
D7
RB8
Stop Bit
TI
Stop Bit Gen.
÷ 16 Reset
RX
Clock
RxD
Bit Detector
Sample Times
Start
Bit
Stop Bit
Receive
Shift
RI
SU01627
Figure 16. Serial Port Mode 2
2002 Jun 06
26
Philips Semiconductors
Preliminary data
80C51 8-bit Flash microcontroller family
P89C51X2/52X2/54X2/58X2
4K/8K/16K/32K Flash
Timer 1
Overflow
80C51 Internal Bus
TB8
Write
to
SBUF
÷2
SMOD = 0
SMOD = 1
S
D
Q
SBUF
TxD
CL
Zero Detector
Start
Data
Shift
TX Control
÷ 16
TX Clock
T1
Send
R1
Load
SBUF
Serial
Port
Interrupt
÷ 16
RX Clock
Sample
RX Control
1-to-0
Transition
Detector
Shift
Start
1FFH
Bit Detector
Input Shift Register
(9 Bits)
Shift
RxD
Load
SBUF
SBUF
Read
SBUF
80C51 Internal Bus
TX
Clock
Write to SBUF
Send
Data
S1P1
Transmit
Shift
TxD
Start Bit
D0
D1
D2
D3
D4
D5
D6
D7
TB8
D0
D1
D2
D3
D4
D5
D6
D7
RB8
Stop Bit
TI
Stop Bit Gen.
RX
Clock
RxD
Bit Detector
Sample Times
÷ 16 Reset
Start
Bit
Stop Bit
Receive
Shift
RI
SU00542
Figure 17. Serial Port Mode 3
2002 Jun 06
27
Philips Semiconductors
Preliminary data
80C51 8-bit Flash microcontroller family
P89C51X2/52X2/54X2/58X2
4K/8K/16K/32K Flash
Slave 1
Enhanced UART operation
In addition to the standard operation modes, the UART can perform
framing error detect by looking for missing stop bits, and automatic
address recognition. The UART also fully supports multiprocessor
communication.
In a more complex system the following could be used to select
slaves 1 and 2 while excluding slave 0:
Automatic Address Recognition
Automatic Address Recognition is a feature which allows the UART
to recognize certain addresses in the serial bit stream by using
hardware to make the comparisons. This feature saves a great deal
of software overhead by eliminating the need for the software to
examine every serial address which passes by the serial port. This
feature is enabled by setting the SM2 bit in SCON. In the 9 bit UART
modes, mode 2 and mode 3, the Receive Interrupt flag (RI) will be
automatically set when the received byte contains either the “Given”
address or the “Broadcast” address. The 9 bit mode requires that
the 9th information bit is a 1 to indicate that the received information
is an address and not data. Automatic address recognition is shown
in Figure 20.
Mode 0 is the Shift Register mode and SM2 is ignored.
Using the Automatic Address Recognition feature allows a master to
selectively communicate with one or more slaves by invoking the
Given slave address or addresses. All of the slaves may be
contacted by using the Broadcast address. Two special Function
Registers are used to define the slave’s address, SADDR, and the
address mask, SADEN. SADEN is used to define which bits in the
SADDR are to be used and which bits are “don’t care”. The SADEN
mask can be logically ANDed with the SADDR to create the “Given”
address which the master will use for addressing each of the slaves.
Use of the Given address allows multiple slaves to be recognized
while excluding others. The following examples will help to show the
versatility of this scheme:
2002 Jun 06
Slave 0
SADDR =
SADEN =
Given
=
1100 0000
1111 1001
1100 0XX0
Slave 1
SADDR =
SADEN =
Given
=
1110 0000
1111 1010
1110 0X0X
Slave 2
SADDR =
SADEN =
Given
=
1110 0000
1111 1100
1110 00XX
In the above example the differentiation among the 3 slaves is in the
lower 3 address bits. Slave 0 requires that bit 0 = 0 and it can be
uniquely addressed by 1110 0110. Slave 1 requires that bit 1 = 0 and
it can be uniquely addressed by 1110 and 0101. Slave 2 requires
that bit 2 = 0 and its unique address is 1110 0011. To select Slaves 0
and 1 and exclude Slave 2 use address 1110 0100, since it is
necessary to make bit 2 = 1 to exclude slave 2.
The 8 bit mode is called Mode 1. In this mode the RI flag will be set
if SM2 is enabled and the information received has a valid stop bit
following the 8 address bits and the information is either a Given or
Broadcast address.
SADDR =
SADEN =
Given
=
1100 0000
1111 1110
1100 000X
In the above example SADDR is the same and the SADEN data is
used to differentiate between the two slaves. Slave 0 requires a 0 in
bit 0 and it ignores bit 1. Slave 1 requires a 0 in bit 1 and bit 0 is
ignored. A unique address for Slave 0 would be 1100 0010 since
slave 1 requires a 0 in bit 1. A unique address for slave 1 would be
1100 0001 since a 1 in bit 0 will exclude slave 0. Both slaves can be
selected at the same time by an address which has bit 0 = 0 (for
slave 0) and bit 1 = 0 (for slave 1). Thus, both could be addressed
with 1100 0000.
When used for framing error detect the UART looks for missing stop
bits in the communication. A missing bit will set the FE bit in the
SCON register. The FE bit shares the SCON.7 bit with SM0 and the
function of SCON.7 is determined by PCON.6 (SMOD0) (see
Figure 18). If SMOD0 is set then SCON.7 functions as FE. SCON.7
functions as SM0 when SMOD0 is cleared. When used as FE
SCON.7 can only be cleared by software. Refer to Figure 19.
Slave 0
SADDR =
SADEN =
Given
=
The Broadcast Address for each slave is created by taking the
logical OR of SADDR and SADEN. Zeros in this result are trended
as don’t-cares. In most cases, interpreting the don’t-cares as ones,
the broadcast address will be FF hexadecimal.
Upon reset SADDR (SFR address 0A9H) and SADEN (SFR
address 0B9H) are leaded with 0s. This produces a given address
of all “don’t cares” as well as a Broadcast address of all “don’t
cares”. This effectively disables the Automatic Addressing mode and
allows the microcontroller to use standard 80C51 type UART drivers
which do not make use of this feature.
1100 0000
1111 1101
1100 00X0
28
Philips Semiconductors
Preliminary data
80C51 8-bit Flash microcontroller family
P89C51X2/52X2/54X2/58X2
4K/8K/16K/32K Flash
SCON Address = 98H
Reset Value = 0000 0000B
Bit Addressable
7
6
5
4
3
2
1
0
SM0/FE
SM1
SM2
REN
TB8
RB8
Tl
Rl
(SMOD0 = 0/1)*
Symbol
Position
Function
FE
SCON.7
Framing Error bit. This bit is set by the receiver when an invalid stop bit is detected. The FE bit is not
cleared by valid frames but should be cleared by software. The SMOD0 bit must be set to enable
access to the FE bit.*
SM0
SCON.7
Serial Port Mode Bit 0, (SMOD0 must = 0 to access bit SM0)
SM1
SCON.6
Serial Port Mode Bit 1
SM0
SM1
Mode
Description
Baud Rate**
0
0
1
0
1
0
0
1
2
shift register
8-bit UART
9-bit UART
1
1
3
9-bit UART
fOSC/12 (12-clk mode) or fOSC/6 (6-clk mode)
variable
fOSC/64 or fOSC/32 or fOSC/16 (6-clock mode) or
fOSC/32 (12-clock mode)
variable
SM2
SCON.5
Enables the Automatic Address Recognition feature in Modes 2 or 3. If SM2 = 1 then Rl will not be set
unless the received 9th data bit (RB8) is 1, indicating an address, and the received byte is a Given or
Broadcast Address. In Mode 1, if SM2 = 1 then Rl will not be activated unless a valid stop bit was
received, and the received byte is a Given or Broadcast Address. In Mode 0, SM2 should be 0.
REN
SCON.4
Enables serial reception. Set by software to enable reception. Clear by software to disable reception.
TB8
SCON.3
The 9th data bit that will be transmitted in Modes 2 and 3. Set or clear by software as desired.
RB8
SCON.2
In modes 2 and 3, the 9th data bit that was received. In Mode 1, if SM2 = 0, RB8 is the stop bit that
was received.
In Mode 0, RB8 is not used.
Tl
SCON.1
Transmit interrupt flag. Set by hardware at the end of the 8th bit time in Mode 0, or at the beginning of
the stop bit in the other modes, in any serial transmission. Must be cleared by software.
Rl
SCON.0
Receive interrupt flag. Set by hardware at the end of the 8th bit time in Mode 0, or halfway through the
stop bit time in the other modes, in any serial reception (except see SM2). Must be cleared by
software.
NOTES:
*SMOD0 is located at PCON.6.
**fOSC = oscillator frequency
SU01628
Figure 18. SCON: Serial Port Control Register
2002 Jun 06
29
Philips Semiconductors
Preliminary data
80C51 8-bit Flash microcontroller family
P89C51X2/52X2/54X2/58X2
4K/8K/16K/32K Flash
D0
D1
D2
D3
D4
D5
D6
D7
D8
DATA BYTE
START
BIT
ONLY IN
MODE 2, 3
STOP
BIT
SET FE BIT IF STOP BIT IS 0 (FRAMING ERROR)
SM0 TO UART MODE CONTROL
SM0 / FE
SM1
SM2
REN
SMOD1
SMOD0
–
POF
TB8
GF1
RB8
TI
GF0
PD
RI
SCON
(98H)
IDL
PCON
(87H)
0 : SCON.7 = SM0
1 : SCON.7 = FE
SU01191
Figure 19. UART Framing Error Detection
D0
D1
D2
D3
D4
SM0
SM1
1
1
1
0
D5
SM2
1
D6
D7
D8
REN
TB8
RB8
1
X
TI
RI
SCON
(98H)
RECEIVED ADDRESS D0 TO D7
COMPARATOR
PROGRAMMED ADDRESS
IN UART MODE 2 OR MODE 3 AND SM2 = 1:
INTERRUPT IF REN=1, RB8=1 AND “RECEIVED ADDRESS” = “PROGRAMMED ADDRESS”
– WHEN OWN ADDRESS RECEIVED, CLEAR SM2 TO RECEIVE DATA BYTES
– WHEN ALL DATA BYTES HAVE BEEN RECEIVED: SET SM2 TO WAIT FOR NEXT ADDRESS.
SU00045
Figure 20. UART Multiprocessor Communication, Automatic Address Recognition
2002 Jun 06
30
Philips Semiconductors
Preliminary data
80C51 8-bit Flash microcontroller family
P89C51X2/52X2/54X2/58X2
4K/8K/16K/32K Flash
Priority Level Structure
Each interrupt source can also be individually programmed to one of
four priority levels by setting or clearing bits in Special Function
Registers IP (Figure 23) and IPH (Figure 24). A lower-priority
interrupt can itself be interrupted by a higher-priority interrupt, but
not by another interrupt of the same level. A high-priority level 3
interrupt can’t be interrupted by any other interrupt source.
Interrupt Priority Structure
0
INT0
IT0
IE0
1
If two request of different priority levels are received simultaneously,
the request of higher priority level is serviced. If requests of the
same priority level are received simultaneously, an internal polling
sequence determines which request is serviced. Thus within each
priority level there is a second priority structure determined by the
polling sequence as follows:
TF0
0
IT1
INT1
IE1
Interrupt
Sources
1
Source
1. IE0 (External Int 0)
2. TF0 (Timer 0)
3. IE1 (External Int 1)
4. TF1 (Timer 1)
5. RI+TI (UART)
6. TF2, EXF2 (Timer 2)
TF1
TI
RI
TF2, EXF2
Priority Within Level
(highest)
(lowest)
SU01521
Note that the “priority within level” structure is only used to resolve
simultaneous requests of the same priority level.
Figure 21. Interrupt Sources
The IP and IPH registers contain a number of unimplemented bits.
User software should not write 1s to these positions, since they may
be used in other 80C51 Family products.
Interrupts
The devices described in this data sheet provide six interrupt
sources. These are shown in Figure 21. The External Interrupts
INT0 and INT1 can each be either level-activated or
transition-activated, depending on bits IT0 and IT1 in Register
TCON. The flags that actually generate these interrupts are bits IE0
and IE1 in TCON. When an external interrupt is generated, the flag
that generated it is cleared by the hardware when the service routine
is vectored to only if the interrupt was transition-activated. If the
interrupt was level-activated, then the external requesting source is
what controls the request flag, rather than the on-chip hardware.
How Interrupts Are Handled
The interrupt flags are sampled at S5P2 of every machine cycle.
The samples are polled during the following machine cycle. If one of
the flags was in a set condition at S5P2 of the preceding cycle, the
polling cycle will find it and the interrupt system will generate an
LCALL to the appropriate service routine, provided this
hardware-generated LCALL is not blocked by any of the following
conditions:
1. An interrupt of equal or higher priority level is already in
progress.
2. The current (polling) cycle is not the final cycle in the execution
of the instruction in progress.
3. The instruction in progress is RETI or any write to the IE or IP
registers.
The Timer 0 and Timer 1 Interrupts are generated by TF0 and TF1,
which are set by a rollover in their respective Timer/Counter
registers (except see Timer 0 in Mode 3). When a timer interrupt is
generated, the flag that generated it is cleared by the on-chip
hardware when the service routine is vectored to.
Any of these three conditions will block the generation of the LCALL
to the interrupt service routine. Condition 2 ensures that the
instruction in progress will be completed before vectoring to any
service routine. Condition 3 ensures that if the instruction in
progress is RETI or any access to IE or IP, then at least one more
instruction will be executed before any interrupt is vectored to.
The Serial Port Interrupt is generated by the logical OR of RI and TI.
Neither of these flags is cleared by hardware when the service
routine is vectored to. In fact, the service routine will normally have
to determine whether it was RI or TI that generated the interrupt,
and the bit will have to be cleared in software.
All of the bits that generate interrupts can be set or cleared by
software, with the same result as though it had been set or cleared
by hardware. That is, interrupts can be generated or pending
interrupts can be canceled in software.
The polling cycle is repeated with each machine cycle, and the
values polled are the values that were present at S5P2 of the
previous machine cycle. Note that if an interrupt flag is active but not
being responded to for one of the above conditions, if the flag is not
still active when the blocking condition is removed, the denied
interrupt will not be serviced. In other words, the fact that the
interrupt flag was once active but not serviced is not remembered.
Every polling cycle is new.
Each of these interrupt sources can be individually enabled or
disabled by setting or clearing a bit in Special Function Register IE
(Figure 22). IE also contains a global disable bit, EA, which disables
all interrupts at once.
2002 Jun 06
31
Philips Semiconductors
Preliminary data
80C51 8-bit Flash microcontroller family
P89C51X2/52X2/54X2/58X2
4K/8K/16K/32K Flash
IE
Address = 0A8H
Reset Value = 0X000000B
Bit Addressable
7
6
5
4
3
2
1
0
EA
—
ET2
ES
ET1
EX1
ET0
EX0
Enable Bit = 1 enables the interrupt.
Enable Bit = 0 disables it.
BIT
IE.7
SYMBOL
EA
IE.6
IE.5
IE.4
IE.3
IE.2
IE.1
IE.0
—
ET2
ES
ET1
EX1
ET0
EX0
FUNCTION
Global disable bit. If EA = 0, all interrupts are disabled. If EA = 1, each interrupt can be individually
enabled or disabled by setting or clearing its enable bit.
Not implemented. Reserved for future use.
Timer 2 interrupt enable bit.
Serial Port interrupt enable bit.
Timer 1 interrupt enable bit.
External interrupt 1 enable bit.
Timer 0 interrupt enable bit.
External interrupt 0 enable bit.
SU01522
Figure 22. Interrupt Enable (IE) Register
IP
Address = 0B8H
Reset Value = xx000000B
Bit Addressable
7
6
5
4
3
2
1
0
—
—
PT2
PS
PT1
PX1
PT0
PX0
Priority Bit = 1 assigns higher priority
Priority Bit = 0 assigns lower priority
BIT
IP.7
IP.6
IP.5
IP.4
IP.3
IP.2
IP.1
IP.0
SYMBOL
—
—
PT2
PS
PT1
PX1
PT0
PX0
FUNCTION
Not implemented, reserved for future use.
Not implemented, reserved for future use.
Timer 2 interrupt priority bit.
Serial Port interrupt priority bit.
Timer 1 interrupt priority bit.
External interrupt 1 priority bit.
Timer 0 interrupt priority bit.
External interrupt 0 priority bit.
SU01523
Figure 23. Interrupt Priority (IP) Register
IPH
Address = B7H
Bit Addressable
Reset Value = xx000000B
7
6
5
4
3
2
1
0
—
—
PT2H
PSH
PT1H
PX1H
PT0H
PX0H
Priority Bit = 1 assigns higher priority
Priority Bit = 0 assigns lower priority
BIT
IPH.7
IPH.6
IPH.5
IPH.4
IPH.3
IPH.2
IPH.1
IPH.0
SYMBOL
—
—
PT2H
PSH
PT1H
PX1H
PT0H
PX0H
FUNCTION
Not implemented, reserved for future use.
Not implemented, reserved for future use.
Timer 2 interrupt priority bit high.
Serial Port interrupt priority bit high.
Timer 1 interrupt priority bit high.
External interrupt 1 priority bit high.
Timer 0 interrupt priority bit high.
External interrupt 0 priority bit high.
Figure 24. Interrupt Priority HIGH (IPH) Register
2002 Jun 06
32
SU01524
Philips Semiconductors
Preliminary data
80C51 8-bit Flash microcontroller family
P89C51X2/52X2/54X2/58X2
4K/8K/16K/32K Flash
.........
C1
S5P2
C2
C3
C4
C5
....
S6
.........
....
....
ε
Interrupt
Goes
Active
Interrupts
Are Polled
Long Call to
Interrupt
Vector Address
Interrupt
Latched
Interrupt Routine
This is the fastest possible response when C2 is the final cycle of an instruction other than RETI or an access to IE or IP.
SU00546
Figure 25. Interrupt Response Timing Diagram
service routine is completed, or else another interrupt will be
generated.
The polling cycle/LCALL sequence is illustrated in Figure 25.
Note that if an interrupt of higher priority level goes active prior to
S5P2 of the machine cycle labeled C3 in Figure 25, then in
accordance with the above rules it will be vectored to during C5 and
C6, without any instruction of the lower priority routine having been
executed.
Response Time
The INT0 and INT1 levels are inverted and latched into IE0 and IE1
at S5P2 of every machine cycle. The values are not actually polled
by the circuitry until the next machine cycle. If a request is active
and conditions are right for it to be acknowledged, a hardware
subroutine call to the requested service routine will be the next
instruction to be executed. The call itself takes two cycles. Thus, a
minimum of three complete machine cycles elapse between
activation of an external interrupt request and the beginning of
execution of the first instruction of the service routine. Figure 25
shows interrupt response timings.
Thus the processor acknowledges an interrupt request by executing
a hardware-generated LCALL to the appropriate servicing routine. In
some cases it also clears the flag that generated the interrupt, and in
other cases it doesn’t. It never clears the Serial Port flag. This has to
be done in the user’s software. It clears an external interrupt flag
(IE0 or IE1) only if it was transition-activated. The
hardware-generated LCALL pushes the contents of the Program
Counter on to the stack (but it does not save the PSW) and reloads
the PC with an address that depends on the source of the interrupt
being vectored to, as shown in Table 8.
A longer response time would result if the request is blocked by one
of the 3 previously listed conditions. If an interrupt of equal or higher
priority level is already in progress, the additional wait time obviously
depends on the nature of the other interrupt’s service routine. If the
instruction in progress is not in its final cycle, the additional wait time
cannot be more the 3 cycles, since the longest instructions (MUL
and DIV) are only 4 cycles long, and if the instruction in progress is
RETI or an access to IE or IP, the additional wait time cannot be
more than 5 cycles (a maximum of one more cycle to complete the
instruction in progress, plus 4 cycles to complete the next instruction
if the instruction is MUL or DIV).
Execution proceeds from that location until the RETI instruction is
encountered. The RETI instruction informs the processor that this
interrupt routine is no longer in progress, then pops the top two
bytes from the stack and reloads the Program Counter. Execution of
the interrupted program continues from where it left off.
Note that a simple RET instruction would also have returned
execution to the interrupted program, but it would have left the
interrupt control system thinking an interrupt was still in progress,
making future interrupts impossible.
Thus, in a single-interrupt system, the response time is always more
than 3 cycles and less than 9 cycles.
External Interrupts
The external sources can be programmed to be level-activated or
transition-activated by setting or clearing bit IT1 or IT0 in Register
TCON. If ITx = 0, external interrupt x is triggered by a detected low
at the INTx pin. If ITx = 1, external interrupt x is edge triggered. In
this mode if successive samples of the INTx pin show a high in one
cycle and a low in the next cycle, interrupt request flag IEx in TCON
is set. Flag bit IEx then requests the interrupt.
As previously mentioned, the derivatives described in this data
sheet have a four-level interrupt structure. The corresponding
registers are IE, IP and IPH. (See Figures 22, 23, and 24.) The IPH
(Interrupt Priority High) register makes the four-level interrupt
structure possible.
The function of the IPH SFR is simple and when combined with the
IP SFR determines the priority of each interrupt. The priority of each
interrupt is determined as shown in the following table:
Since the external interrupt pins are sampled once each machine
cycle, an input high or low should hold for at least 12 oscillator
periods to ensure sampling. If the external interrupt is
transition-activated, the external source has to hold the request pin
high for at least one cycle, and then hold it low for at least one cycle.
This is done to ensure that the transition is seen so that interrupt
request flag IEx will be set. IEx will be automatically cleared by the
CPU when the service routine is called.
PRIORITY BITS
If the external interrupt is level-activated, the external source has to
hold the request active until the requested interrupt is actually
generated. Then it has to deactivate the request before the interrupt
2002 Jun 06
33
INTERRUPT PRIORITY LEVEL
IPH.x
IP.x
0
0
Level 0 (lowest priority)
0
1
Level 1
1
0
Level 2
1
1
Level 3 (highest priority)
Philips Semiconductors
Preliminary data
80C51 8-bit Flash microcontroller family
P89C51X2/52X2/54X2/58X2
4K/8K/16K/32K Flash
interrupt is being serviced, it will be stopped and the new interrupt
serviced. When the new interrupt is finished, the lower priority level
interrupt that was stopped will be completed.
An interrupt will be serviced as long as an interrupt of equal or
higher priority is not already being serviced. If an interrupt of equal
or higher level priority is being serviced, the new interrupt will wait
until it is finished before being serviced. If a lower priority level
Table 8.
Interrupt Table
SOURCE
POLLING PRIORITY
REQUEST BITS
HARDWARE CLEAR?
N
(L)1
Y
VECTOR ADDRESS
(T)2
External interrupt 0
1
IE0
Timer 0
2
TF0
Y
03H
External interrupt 1
3
IE1
N (L) Y (T)
13H
Timer 1
4
TF1
Y
1BH
UART
5
RI, TI
N
23H
Timer 2
6
TF2, EXF2
N
2BH
0BH
NOTES:
1. L = Level activated
2. T = Transition activated
Note that bit 2 is not writable and is always read as a zero. This
allows the DPS bit to be quickly toggled simply by executing an INC
DPTR instruction without affecting the WUPD bit.
Reduced EMI
All port pins have slew rate controlled outputs. This is to limit noise
generated by quickly switching output signals. The slew rate is
factory set to approximately 10 ns rise and fall times.
Reduced EMI Mode
The AO bit (AUXR.0) in the AUXR register when set disables the
ALE output.
DPS
BIT0
AUXR1
AUXR (8EH)
DPTR1
DPTR0
7
6
5
4
3
2
1
0
–
–
–
–
–
–
–
AO
AUXR.0
AO
DPH
(83H)
DPL
(82H)
Turns off ALE output.
EXTERNAL
DATA
MEMORY
SU00745A
Figure 26.
Dual DPTR
The dual DPTR structure (see Figure 26) enables a way to specify
the address of an external data memory location. There are two
16-bit DPTR registers that address the external memory, and a
single bit called DPS = AUXR1/bit0 that allows the program code to
switch between them.
DPTR Instructions
The instructions that refer to DPTR refer to the data pointer that is
currently selected using the AUXR1/bit 0 register. The six
instructions that use the DPTR are as follows:
• New Register Name: AUXR1#
• SFR Address: A2H
• Reset Value: xxx000x0B
AUXR1 (A2H)
7
6
5
4
3
2
1
0
–
–
–
–
WUPD
0
–
DPS
Where:
DPS = AUXR1/bit0 = Switches between DPTR0 and DPTR1.
Select Reg
DPS
DPTR0
0
DPTR1
1
Increments the data pointer by 1
MOV DPTR, #data16
Loads the DPTR with a 16-bit constant
MOV A, @ A+DPTR
Move code byte relative to DPTR to ACC
MOVX A, @ DPTR
Move external RAM (16-bit address) to
ACC
MOVX @ DPTR , A
Move ACC to external RAM (16-bit
address)
JMP @ A + DPTR
Jump indirect relative to DPTR
The data pointer can be accessed on a byte-by-byte basis by
specifying the low or high byte in an instruction which accesses the
SFRs. See application note AN458 for more details.
The DPS bit status should be saved by software when switching
between DPTR0 and DPTR1.
2002 Jun 06
INC DPTR
34
Philips Semiconductors
Preliminary data
80C51 8-bit Flash microcontroller family
P89C51X2/52X2/54X2/58X2
4K/8K/16K/32K Flash
ABSOLUTE MAXIMUM RATINGS1, 2, 3
PARAMETER
Operating temperature under bias
RATING
UNIT
0 to +70 or –40 to +85
°C
–65 to +150
°C
0 to +13.0
V
Storage temperature range
Voltage on EA/VPP pin to VSS
Voltage on any other pin to VSS
Maximum IOL per I/O pin
–0.5 to +6.5
V
15
mA
Power dissipation (based on package heat transfer limitations, not device power consumption)
1.5
W
NOTES:
1. Stresses above those listed under Absolute Maximum Ratings may cause permanent damage to the device. This is a stress rating only and
functional operation of the device at these or any conditions other than those described in the AC and DC Electrical Characteristics section
of this specification is not implied.
2. This product includes circuitry specifically designed for the protection of its internal devices from the damaging effects of excessive static
charge. Nonetheless, it is suggested that conventional precautions be taken to avoid applying greater than the rated maximum.
3. Parameters are valid over operating temperature range unless otherwise specified. All voltages are with respect to VSS unless otherwise
noted.
AC ELECTRICAL CHARACTERISTICS
Tamb = 0°C to +70°C or –40°C to +85°C
CLOCK FREQUENCY
RANGE
SYMBOL
1/tCLCL
2002 Jun 06
FIGURE
PARAMETER
31
Oscillator frequency
OPERATING MODE
POWER SUPPLY
VOLTAGE
MIN
MAX
UNIT
6-clock
5 V " 10%
0
20
MHz
12-clock
5 V " 10%
0
33
MHz
35
Philips Semiconductors
Preliminary data
80C51 8-bit Flash microcontroller family
P89C51X2/52X2/54X2/58X2
4K/8K/16K/32K Flash
DC ELECTRICAL CHARACTERISTICS
Tamb = 0 °C to +70 °C or –40 °C to +85 °C; VCC = 5 V ±10%; VSS = 0 V (20/33 MHz max. CPU clock)
SYMBOL
PARAMETER
TEST
CONDITIONS
LIMITS
MIN
VIL
Input low
VIH
voltage11
UNIT
TYP1
MAX
4.5 V < VCC < 5.5 V
–0.5
0.2 VCC–0.1
V
Input high voltage (ports 0, 1, 2, 3, EA)
–
0.2 VCC+0.9
VCC+0.5
V
VIH1
Input high voltage, XTAL1, RST11
–
0.7 VCC
VCC+0.5
V
VOL
Output low voltage, ports 1, 2, 3 8
VCC = 4.5 V; IOL = 1.6 mA2
–
0.4
V
VOL1
Output low voltage, port 0, ALE, PSEN 7, 8
VCC = 4.5 V; IOL = 3.2 mA2
–
0.4
V
VOH
Output high voltage, ports 1, 2, 3 3
VCC = 4.5 V; IOH = –30 mA
VCC – 0.7
–
V
VOH1
Output high voltage (port 0 in external bus
mode), ALE9, PSEN3
VCC = 4.5 V; IOH = –3.2 mA
VCC – 0.7
–
V
IIL
Logical 0 input current, ports 1, 2, 3
VIN = 0.4 V
–1
–50
mA
ITL
Logical 1-to-0 transition current, ports 1, 2, 36
VIN = 2.0 V; See note 4
–
–650
mA
ILI
Input leakage current, port 0
0.45 < VIN < VCC – 0.3
–
±10
mA
ICC
Power supply current (see Figure 34):
100
mA
Active mode (see Note 5)
Idle mode (see Note 5)
Power-down mode or clock stopped
(see Figure 38 for conditions)
Tamb = 0 °C to 70 °C
15
Tamb = –40 °C to +85 °C
125
mA
RRST
Internal reset pull-down resistor
–
40
225
kΩ
CIO
Pin capacitance10 (except EA)
–
–
15
pF
NOTES:
1. Typical ratings are not guaranteed. The values listed are at room temperature, 5 V.
2. Capacitive loading on ports 0 and 2 may cause spurious noise to be superimposed on the VOLs of ALE and ports 1 and 3. The noise is due
to external bus capacitance discharging into the port 0 and port 2 pins when these pins make 1-to-0 transitions during bus operations. In the
worst cases (capacitive loading > 100 pF), the noise pulse on the ALE pin may exceed 0.8 V. In such cases, it may be desirable to qualify
ALE with a Schmitt Trigger, or use an address latch with a Schmitt Trigger STROBE input. IOL can exceed these conditions provided that no
single output sinks more than 5 mA and no more than two outputs exceed the test conditions.
3. Capacitive loading on ports 0 and 2 may cause the VOH on ALE and PSEN to momentarily fall below the VCC–0.7 specification when the
address bits are stabilizing.
4. Pins of ports 1, 2 and 3 source a transition current when they are being externally driven from 1 to 0. The transition current reaches its
maximum value when VIN is approximately 2 V.
5. See Figures 35 through 38 for ICC test conditions and Figure 34 for ICC vs. Frequency.
12-clock mode characteristics:
Active mode:
ICC (MAX) = (8.5 + 0.62 FREQ. [MHz])mA
Idle mode:
ICC (MAX) = (3.5 + 0.18 FREQ. [MHz])mA
6. This value applies to Tamb = 0°C to +70°C. For Tamb = –40°C to +85°C, ITL = –750 µΑ.
7. Load capacitance for port 0, ALE, and PSEN = 100 pF, load capacitance for all other outputs = 80 pF.
8. Under steady state (non-transient) conditions, IOL must be externally limited as follows:
15 mA (*NOTE: This is 85 °C specification.)
Maximum IOL per port pin:
Maximum IOL per 8-bit port:
26 mA
71 mA
Maximum total IOL for all outputs:
If IOL exceeds the test condition, VOL may exceed the related specification. Pins are not guaranteed to sink current greater than the listed
test conditions.
9. ALE is tested to VOH1, except when ALE is off then VOH is the voltage specification.
10. Pin capacitance is characterized but not tested. Pin capacitance is less than 25 pF. Pin capacitance of ceramic package is less than 15 pF
(except EA is 25 pF).
11. To improve noise rejection a nominal 100 ns glitch rejection circuitry has been added to the RST pin, and a nominal 15 ns glitch rejection
circuitry has been added to the INT0 and INT1 pins. Previous devices provided only an inherent 5 ns of glitch rejection.
2002 Jun 06
36
Philips Semiconductors
Preliminary data
80C51 8-bit Flash microcontroller family
P89C51X2/52X2/54X2/58X2
4K/8K/16K/32K Flash
AC ELECTRICAL CHARACTERISTICS (12-CLOCK MODE)
Tamb = 0 °C to +70 °C or –40 °C to +85 °C ; VCC = 5 V ±10%, VSS = 0 V1,2,3,4
Symbol
Figure
Parameter
Limits
16 MHz Clock
MIN
MAX
33
MIN
Unit
MAX
1/tCLCL
31
Oscillator frequency
0
tLHLL
27
ALE pulse width
2 tCLCL–8
117
MHz
ns
tAVLL
27
Address valid to ALE low
tCLCL –13
49.5
ns
tLLAX
27
Address hold after ALE low
tCLCL –20
tLLIV
27
ALE low to valid instruction in
tLLPL
27
ALE low to PSEN low
tCLCL –10
52.5
ns
tPLPH
27
PSEN pulse width
3 tCLCL –10
177.5
ns
tPLIV
27
PSEN low to valid instruction in
tPXIX
27
Input instruction hold after PSEN
tPXIZ
27
Input instruction float after PSEN
tCLCL –10
52.5
ns
tAVIV
27
Address to valid instruction in
5 tCLCL –35
277.5
ns
tPLAZ
27
PSEN low to address float
10
10
ns
42.5
4 tCLCL –35
3 tCLCL –35
0
ns
215
152.5
0
ns
ns
ns
Data Memory
tRLRH
28
RD pulse width
6 tCLCL –20
355
tWLWH
29
WR pulse width
6 tCLCL –20
355
tRLDV
28
RD low to valid data in
tRHDX
28
Data hold after RD
tRHDZ
28
Data float after RD
2 tCLCL –10
115
ns
tLLDV
28
ALE low to valid data in
8 tCLCL –35
465
ns
tAVDV
28
Address to valid data in
9 tCLCL –35
527.5
ns
tLLWL
28, 29
ALE low to RD or WR low
3 tCLCL –15
202.5
ns
tAVWL
28, 29
Address valid to WR low or RD low
4 tCLCL –15
235
ns
tQVWX
29
Data valid to WR transition
tCLCL –25
37.5
ns
tWHQX
29
Data hold after WR
tCLCL –15
47.5
ns
tQVWH
29
Data valid to WR high
7 tCLCL –5
tRLAZ
28
RD low to address float
tWHLH
28, 29
RD or WR high to ALE high
tCLCL –10
tCLCL +10
5 tCLCL –35
0
ns
ns
277.5
0
3 tCLCL +15
172.5
ns
432.5
0
52.5
ns
ns
0
ns
72.5
ns
External Clock
tCHCX
31
High time
0.32 tCLCL
tCLCL – tCLCX
ns
tCLCX
31
Low time
0.32 tCLCL
tCLCL – tCHCX
ns
tCLCH
31
Rise time
5
ns
tCHCL
31
Fall time
5
ns
Shift register
tXLXL
30
Serial port clock cycle time
12 tCLCL
750
ns
tQVXH
30
Output data setup to clock rising edge
10 tCLCL –25
600
ns
tXHQX
30
Output data hold after clock rising edge
2 tCLCL –15
110
ns
tXHDX
30
Input data hold after clock rising edge
0
tXHDV
30
Clock rising edge to input data valid
0
10 tCLCL –133
ns
492
ns
NOTES:
1. Parameters are valid over operating temperature range unless otherwise specified.
2. Load capacitance for port 0, ALE, and PSEN = 100 pF, load capacitance for all outputs = 80 pF
3. Interfacing the microcontroller to devices with float time up to 45 ns is permitted. This limited bus contention will not cause damage to port 0
drivers.
4. Parts are guaranteed by design to operate down to 0 Hz.
2002 Jun 06
37
Philips Semiconductors
Preliminary data
80C51 8-bit Flash microcontroller family
P89C51X2/52X2/54X2/58X2
4K/8K/16K/32K Flash
AC ELECTRICAL CHARACTERISTICS (6-CLOCK MODE)
Tamb = 0 °C to +70 °C or –40 °C to +85 °C ; VCC = 5 V ±10%, VSS = 0 V1,2,3,4,5
Symbol
Figure
Parameter
Limits
16 MHz Clock
MIN
MAX
20
MIN
Unit
MAX
1/tCLCL
31
Oscillator frequency
0
tLHLL
27
ALE pulse width
tCLCL–8
54.5
MHz
ns
tAVLL
27
Address valid to ALE low
0.5 tCLCL –13
18.25
ns
tLLAX
27
Address hold after ALE low
0.5 tCLCL –20
tLLIV
27
ALE low to valid instruction in
tLLPL
27
ALE low to PSEN low
0.5 tCLCL –10
21.25
ns
tPLPH
27
PSEN pulse width
1.5 tCLCL –10
83.75
ns
tPLIV
27
PSEN low to valid instruction in
tPXIX
27
Input instruction hold after PSEN
tPXIZ
27
Input instruction float after PSEN
0.5 tCLCL –10
21.25
ns
tAVIV
27
Address to valid instruction in
2.5 tCLCL –35
121.25
ns
tPLAZ
27
Data Memory
PSEN low to address float
10
10
ns
tRLRH
28
RD pulse width
3 tCLCL –20
tWLWH
29
WR pulse width
3 tCLCL –20
tRLDV
28
RD low to valid data in
tRHDX
28
Data hold after RD
tRHDZ
28
Data float after RD
tCLCL –10
52.5
ns
tLLDV
28
ALE low to valid data in
4 tCLCL –35
215
ns
tAVDV
28
Address to valid data in
4.5 tCLCL –35
246.25
ns
tLLWL
28, 29
ALE low to RD or WR low
1.5 tCLCL –15
108.75
ns
tAVWL
28, 29
Address valid to WR low or RD low
2 tCLCL –15
110
ns
tQVWX
29
Data valid to WR transition
0.5 tCLCL –25
6.25
ns
tWHQX
29
Data hold after WR
0.5 tCLCL –15
16.25
ns
tQVWH
29
Data valid to WR high
3.5 tCLCL –5
213.75
tRLAZ
28
RD low to address float
11.25
2 tCLCL –35
1.5 tCLCL –35
0
ns
90
58.75
0
ns
167.5
0
ns
121.25
0
1.5 tCLCL +15
78.75
0
21.25
ns
ns
167.5
2.5 tCLCL –35
ns
ns
ns
ns
0
ns
41.25
ns
tWHLH
28, 29
External Clock
RD or WR high to ALE high
0.5 tCLCL –10
0.5 tCLCL +10
tCHCX
31
High time
0.4 tCLCL
tCLCL – tCLCX
ns
tCLCX
31
Low time
0.4 tCLCL
tCLCL – tCHCX
ns
tCLCH
31
Rise time
5
ns
tCHCL
31
Shift register
Fall time
5
ns
tXLXL
30
Serial port clock cycle time
6 tCLCL
375
ns
tQVXH
30
Output data setup to clock rising edge
5 tCLCL –25
287.5
ns
tXHQX
30
Output data hold after clock rising edge
tCLCL –15
47.5
ns
tXHDX
30
Input data hold after clock rising edge
0
tXHDV
30
Clock rising edge to input data valid
0
5 tCLCL –133
ns
179.5
ns
NOTES:
1. Parameters are valid over operating temperature range unless otherwise specified.
2. Load capacitance for port 0, ALE, and PSEN=100 pF, load capacitance for all outputs = 80 pF
3. Interfacing the microcontroller to devices with float time up to 45ns is permitted. This limited bus contention will not cause damage to port 0
drivers.
4. Parts are guaranteed by design to operate down to 0 Hz.
5. Data shown in the table are the best mathematical models for the set of measured values obtained in tests. If a particular parameter
calculated at a customer specified frequency has a negative value, it should be considered equal to zero.
2002 Jun 06
38
Philips Semiconductors
Preliminary data
80C51 8-bit Flash microcontroller family
P89C51X2/52X2/54X2/58X2
4K/8K/16K/32K Flash
EXPLANATION OF THE AC SYMBOLS
P – PSEN
Q – Output data
R – RD signal
t – Time
V – Valid
W – WR signal
X – No longer a valid logic level
Z – Float
Examples: tAVLL = Time for address valid to ALE low.
tLLPL =Time for ALE low to PSEN low.
Each timing symbol has five characters. The first character is always
‘t’ (= time). The other characters, depending on their positions,
indicate the name of a signal or the logical status of that signal. The
designations are:
A – Address
C – Clock
D – Input data
H – Logic level high
I – Instruction (program memory contents)
L – Logic level low, or ALE
tLHLL
ALE
tAVLL
tLLPL
tPLPH
tLLIV
tPLIV
PSEN
tLLAX
INSTR IN
A0–A7
PORT 0
tPXIZ
tPLAZ
tPXIX
A0–A7
tAVIV
PORT 2
A0–A15
A8–A15
SU00006
Figure 27. External Program Memory Read Cycle
ALE
tWHLH
PSEN
tLLDV
tLLWL
tRLRH
RD
tAVLL
tLLAX
tRLAZ
PORT 0
tRHDZ
tRLDV
tRHDX
A0–A7
FROM RI OR DPL
DATA IN
A0–A7 FROM PCL
INSTR IN
tAVWL
tAVDV
PORT 2
P2.0–P2.7 OR A8–A15 FROM DPF
A0–A15 FROM PCH
SU00025
Figure 28. External Data Memory Read Cycle
2002 Jun 06
39
Philips Semiconductors
Preliminary data
80C51 8-bit Flash microcontroller family
P89C51X2/52X2/54X2/58X2
4K/8K/16K/32K Flash
ALE
tWHLH
PSEN
tWLWH
tLLWL
WR
tLLAX
tAVLL
tWHQX
tQVWX
tQVWH
A0–A7
FROM RI OR DPL
PORT 0
DATA OUT
A0–A7 FROM PCL
INSTR IN
tAVWL
PORT 2
P2.0–P2.7 OR A8–A15 FROM DPF
A0–A15 FROM PCH
SU00026
Figure 29. External Data Memory Write Cycle
INSTRUCTION
0
1
2
3
4
5
6
7
8
ALE
tXLXL
CLOCK
tXHQX
tQVXH
OUTPUT DATA
0
1
2
WRITE TO SBUF
3
4
5
6
7
tXHDX
tXHDV
SET TI
INPUT DATA
VALID
VALID
VALID
VALID
VALID
VALID
VALID
VALID
CLEAR RI
SET RI
SU00027
Figure 30. Shift Register Mode Timing
VCC–0.5
0.45V
0.7VCC
0.2VCC–0.1
tCHCL
tCHCX
tCLCH
tCLCX
tCLCL
SU00009
Figure 31. External Clock Drive
2002 Jun 06
40
Philips Semiconductors
Preliminary data
80C51 8-bit Flash microcontroller family
P89C51X2/52X2/54X2/58X2
4K/8K/16K/32K Flash
VCC–0.5
VLOAD+0.1V
0.2VCC+0.9
VLOAD
0.45V
0.2VCC–0.1
VLOAD–0.1V
TIMING
REFERENCE
POINTS
SU00717
SU00718
Figure 32. AC Testing Input/Output
Figure 33. Float Waveform
30
MAX ACTIVE MODE
ICC(mA)
25
TYP ACTIVE MODE
20
15
10
MAX IDLE MODE
TYP IDLE MODE
5
8
12
16
20
24
28
32
36
FREQ AT XTAL1 (MHz)
SU01630
Figure 34. ICC vs. FREQ for 12-clock operation
Valid only within frequency specifications
2002 Jun 06
VOL+0.1V
NOTE:
For timing purposes, a port is no longer floating when a 100mV change from
load voltage occurs, and begins to float when a 100mV change from the loaded
VOH/VOL level occurs. IOH/IOL ≥ ±20mA.
NOTE:
AC inputs during testing are driven at VCC –0.5 for a logic ‘1’ and 0.45V for a logic ‘0’.
Timing measurements are made at VIH min for a logic ‘1’ and VIL max for a logic ‘0’.
4
VOH–0.1V
41
Philips Semiconductors
Preliminary data
80C51 8-bit Flash microcontroller family
P89C51X2/52X2/54X2/58X2
4K/8K/16K/32K Flash
VCC
VCC
ICC
ICC
VCC
VCC
VCC
VCC
RST
RST
P0
P0
EA
EA
(NC)
XTAL2
(NC)
XTAL2
CLOCK SIGNAL
XTAL1
CLOCK SIGNAL
XTAL1
VSS
VSS
SU00719
SU00720
Figure 35. ICC Test Condition, Active Mode
All other pins are disconnected
VCC–0.5
Figure 36. ICC Test Condition, Idle Mode
All other pins are disconnected
0.7VCC
0.2VCC–0.1
0.45V
tCHCL
tCHCX
tCLCH
tCLCX
tCLCL
SU00009
Figure 37. Clock Signal Waveform for ICC Tests in Active and Idle Modes
tCLCH = tCHCL = 5ns
VCC
ICC
VCC
VCC
RST
P0
EA
(NC)
XTAL2
XTAL1
VSS
SU00016
Figure 38. ICC Test Condition, Power Down Mode
All other pins are disconnected. VCC = 2 V to 5.5 V
2002 Jun 06
VCC
42
Philips Semiconductors
Preliminary data
80C51 8-bit Flash microcontroller family
P89C51X2/52X2/54X2/58X2
4K/8K/16K/32K Flash
Security
The security feature protects against software piracy and prevents the contents of the FLASH from being read. The Security Lock bits are
located in FLASH. The P89C51X2/P89C52X2/P89C54X2/P89C58X2 has 3 programmable security lock bits that will provide different levels of
protection for the on-chip code and data (see Table 9). Unlike the ROM and OTP versions, the security lock bits are independent. LB3 includes
the security protection of LB1.
Table 9.
SECURITY LOCK BITS1
PROTECTION DESCRIPTION
Level
LB1
MOVC instructions executed from external program memory are disabled from fetching code bytes from
internal memory.
LB2
Program verification is disabled
LB3
External execution is disabled.
NOTE:
1. The security lock bits are independent.
2002 Jun 06
43
Philips Semiconductors
Preliminary data
80C51 8-bit Flash microcontroller family
P89C51X2/52X2/54X2/58X2
4K/8K/16K/32K Flash
DIP40: plastic dual in-line package; 40 leads (600 mil)
2002 Jun 06
44
SOT129-1
Philips Semiconductors
Preliminary data
80C51 8-bit Flash microcontroller family
P89C51X2/52X2/54X2/58X2
4K/8K/16K/32K Flash
PLCC44: plastic leaded chip carrier; 44 leads
2002 Jun 06
SOT187-2
45
Philips Semiconductors
Preliminary data
80C51 8-bit Flash microcontroller family
P89C51X2/52X2/54X2/58X2
4K/8K/16K/32K Flash
LQFP44: plastic low profile quad flat package; 44 leads; body 10 x 10 x 1.4 mm
2002 Jun 06
46
SOT389-1
Philips Semiconductors
Preliminary data
80C51 8-bit Flash microcontroller family
P89C51X2/52X2/54X2/58X2
4K/8K/16K/32K Flash
REVISION HISTORY
Date
CPCN
Description
2002 Jun 06
9397 750 09928
Added device comparison table
2002 Feb 28
9397 750 09537
Initial release
2002 Jun 06
47
Philips Semiconductors
Preliminary data
80C51 8-bit Flash microcontroller family
P89C51X2/52X2/54X2/58X2
4K/8K/16K/32K Flash
Data sheet status
Data sheet status [1]
Product
status [2]
Definitions
Objective data
Development
This data sheet contains data from the objective specification for product development.
Philips Semiconductors reserves the right to change the specification in any manner without notice.
Preliminary data
Qualification
This data sheet contains data from the preliminary specification. Supplementary data will be
published at a later date. Philips Semiconductors reserves the right to change the specification
without notice, in order to improve the design and supply the best possible product.
Product data
Production
This data sheet contains data from the product specification. Philips Semiconductors reserves the
right to make changes at any time in order to improve the design, manufacturing and supply.
Changes will be communicated according to the Customer Product/Process Change Notification
(CPCN) procedure SNW-SQ-650A.
[1] Please consult the most recently issued data sheet before initiating or completing a design.
[2] The product status of the device(s) described in this data sheet may have changed since this data sheet was published. The latest information is available on the Internet at URL
http://www.semiconductors.philips.com.
Definitions
Short-form specification — The data in a short-form specification is extracted from a full data sheet with the same type number and title. For
detailed information see the relevant data sheet or data handbook.
Limiting values definition — Limiting values given are in accordance with the Absolute Maximum Rating System (IEC 60134). Stress above one
or more of the limiting values may cause permanent damage to the device. These are stress ratings only and operation of the device at these or
at any other conditions above those given in the Characteristics sections of the specification is not implied. Exposure to limiting values for extended
periods may affect device reliability.
Application information — Applications that are described herein for any of these products are for illustrative purposes only. Philips
Semiconductors make no representation or warranty that such applications will be suitable for the specified use without further testing or
modification.
Disclaimers
Life support — These products are not designed for use in life support appliances, devices or systems where malfunction of these products can
reasonably be expected to result in personal injury. Philips Semiconductors customers using or selling these products for use in such applications
do so at their own risk and agree to fully indemnify Philips Semiconductors for any damages resulting from such application.
Right to make changes — Philips Semiconductors reserves the right to make changes, without notice, in the products, including circuits, standard
cells, and/or software, described or contained herein in order to improve design and/or performance. Philips Semiconductors assumes no
responsibility or liability for the use of any of these products, conveys no license or title under any patent, copyright, or mask work right to these
products, and makes no representations or warranties that these products are free from patent, copyright, or mask work right infringement, unless
otherwise specified.
 Koninklijke Philips Electronics N.V. 2002
All rights reserved. Printed in U.S.A.
Contact information
For additional information please visit
http://www.semiconductors.philips.com.
Fax: +31 40 27 24825
Date of release: 06-02
For sales offices addresses send e-mail to:
[email protected].
Document order number:
2002 Jun 06
48
9397 750 09928