INTEL 8XC51R

8XC51RA/RB/RC
CHMOS SINGLE-CHIP 8-BIT MICROCONTROLLER
Commercial/Express
87C51RA/83C51RA/80C51RA/87C51RB/83C51RB/87C51RC/83C51RC
*See Table 1 for Proliferation Options
Y
High Performance CHMOS EPROM/
ROM/CPU
Y
6 Interrupt Sources
Y
Programmable Serial Channel with:
Ð Framing Error Detection
Ð Automatic Address Recognition
Y
24 MHz Operation
Y
512 Bytes of On-Chip Data RAM
Dedicated Hardware Watchdog Timer
(One-Time Enabled with Reset-Out)
Y
Y
TTL and CMOS Compatible Logic
Levels
Three 16-Bit Timer/Counters
Y
Y
64K External Program Memory Space
Programmable Clock Out
Y
64K External Data Memory Space
Up/Down Timer/Counter
Y
MCSÉ 51 Compatible Instruction Set
Y
Three Level Program Lock System
Y
Y
8K/16K/32K On-Chip Program Memory
Power Saving Idle and Power Down
Modes
Y
Improved Quick Pulse Programming
Algorithm
ONCE (On-Circuit Emulation) Mode
Y
Y
Four-Level Interrupt Priority
Y
Extended Temperature Range
( b 40§ C to a 85§ C)
Y
Y
Y
Boolean Processor
Y
32 Programmable I/O Lines
MEMORY ORGANIZATION
ROMless
Device
ROM
Device
EPROM
Version
ROM/EPROM
Bytes
RAM
Bytes
80C51RA
83C51RA
80C51RA
83C51RB
87C51RA
8K
512
87C51RB
16K
512
80C51RA
83C51RC
87C51RC
32K
512
These devices can address up to 64 Kbytes of external program/data memory.
The Intel 8XC51RA/8XC51RB/8XC51RC is a single-chip control-oriented microcontroller which is fabricated
on Intel’s reliable CHMOS III-E technology. Being a member of the MCS 51 family of controllers, the
8XC51RA/8XC51RB/8XC51RC uses the same powerful instruction set, has the same architecture, and is pinfor-pin compatible with the existing MCS 51 family of products. The 8XC51RA/8XC51RB/8XC51RC is an
enhanced version of the 8XC52/8XC54/8XC58. The added features make it an even more powerful microcontroller for applications that require 512 bytes of on-chip data RAM and dedicated hardware WatchDog Timer
with reset-out features.
Throughout this document 8XC51RX will refer to the 8XC51RA, 8XC51RB and 8XC51RC unless information
applies to a specific device.
For a detailed description of 8XC51RA/RB/RC, refer to the 8XC51RA/RB/RC Hardware Description, order
number 272668.
*Other brands and names are the property of their respective owners.
Information in this document is provided in connection with Intel products. Intel assumes no liability whatsoever, including infringement of any patent or
copyright, for sale and use of Intel products except as provided in Intel’s Terms and Conditions of Sale for such products. Intel retains the right to make
changes to these specifications at any time, without notice. Microcomputer Products may have minor variations to this specification known as errata.
COPYRIGHT © INTEL CORPORATION, 1995
December 1995
Order Number: 272659-002
8XC51RA/RB/RC
Table 1. Proliferations Options
80C51RA
Standard*1
X
-1
X
-20
X
-24
X
83C51RA
87C51RA
X
X
X
X
X
X
X
X
83C51RB
X
X
X
X
87C51RB
X
X
X
X
83C51RC
87C51RC
X
X
X
X
X
X
X
X
NOTES:
*1 3.5
-1 3.5
-20 3.5
-24 3.5
MHz
MHz
MHz
MHz
to
to
to
to
12
16
20
24
MHz;
MHz;
MHz;
MHz;
5V
5V
5V
5V
g 20%
g 20%
g 20%
g 10%
272659 – 4
Figure 1. 8XC51RX Block Diagram
2
8XC51RA/RB/RC
PROCESS INFORMATION
PACKAGES
This device is manufactured on P629.5, a CHMOS
III-E process. Additional process and reliability information is available in Intel’s Components Quality
and Reliability Handbook, Order No. 210997.
Part
Prefix
Package Type
8XC51RX
8XC51RX
8XC51RX
P
N
S
40-Pin Plastic DIP (OTP)
44-Pin PLCC (OTP)
44-Pin QFP (OTP)
272659 – 2
PLCC
272659 – 1
DIP
272659 – 3
*Do not connect reserved pins.
QFP
Figure 2. Pin Connections
3
8XC51RA/RB/RC
PIN DESCRIPTIONS
VCC: Supply voltage.
VSS: Circuit ground.
VSS1: Secondary ground (not on DIP). Provided to
reduce ground bounce and improve power supply
by-passing.
NOTE:
This pin is not a substitute for the VSS pin (pin 22).
(Connection not necessary for proper operation.)
Port 0: Port 0 is an 8-bit, open drain, bidirectional
I/O port. As an output port each pin can sink several
LS TTL inputs. Port 0 pins that have 1’s written to
them float, and in that state 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 pullups when emitting 1’s, and can source and
sink several LS TTL inputs.
Port 0 also receives the code bytes during EPROM
programming, and outputs the code bytes during
program verification. External pullup resistors are required during program verification.
Port 1: Port 1 is an 8-bit bidirectional I/O port with
internal pullups. The Port 1 output buffers can drive
LS TTL inputs. Port 1 pins that have 1’s written to
them are pulled high by the internal pullups, and in
that state can be used as inputs. As inputs, Port 1
pins that are externally pulled low will source current
(IIL, on the data sheet) because of the internal pullups.
In addition, Port 1 serves the functions of the following special features of the 8XC51RX:
Port Pin
Alternate Function
P1.0
T2 (External Count Input to Timer/
Counter 2), Clock-Out
T2EX (Timer/Counter 2 Capture/
Reload Trigger and Direction Control)
P1.1
Port 1 receives the low-order address bytes during
EPROM programming and verifying.
Port 2: Port 2 is an 8-bit bidirectional I/O port with
internal pullups. The Port 2 output buffers can drive
4
LS TTL inputs. Port 2 pins that have 1’s written to
them are pulled high by the internal pullups, and in
that state can be used as inputs. As inputs, Port 2
pins that are externally pulled low will source current
(IIL, on the data sheet) because of the internal pullups.
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 pullups when emitting 1’s. During accesses to external Data Memory that use 8-bit
addresses (MOVX @ Ri), Port 2 emits the contents of
the P2 Special Function Register.
Some Port 2 pins receive the high-order address bits
during EPROM programming and program verification.
Port 3: Port 3 is an 8-bit bidirectional I/O port with
internal pullups. The Port 3 output buffers can drive
LS TTL inputs. Port 3 pins that have 1’s written to
them are pulled high by the internal pullups, and in
that state can be used as inputs. As inputs, Port 3
pins that are externally pulled low will source current
(IIL, on the data sheet) because of the pullups.
Port 3 also serves the functions of various special
features of the 8051 Family, as listed below:
Port Pin
Alternate Function
P3.0
P3.1
P3.2
P3.3
P3.4
P3.5
P3.6
P3.7
RXD (serial input port)
TXD (serial output port)
INT0 (external interrupt 0)
INT1 (external interrupt 1)
T0 (Timer 0 external input)
T1 (Timer 1 external input)
WR (external data memory write strobe)
RD (external data memory read strobe)
RST: Reset I/O. A high on this pin for two machine
cycles while the oscillator is running resets the device. The port pins will be driven to their reset condition when a minimum VIHI voltage is applied whether
the oscillator is running or not. An internal pulldown
resistor permits a power-on reset with only a capacitor connected to VCC. After a WatchDog Timer overflow, this RST pin will drive an output high pulse at a
minimum VOH2 for 96 x TOSC duration while the internal reset signal is active.
ALE: Address Latch Enable output pulse for latching
the low byte of the address during accesses to ex-
8XC51RA/RB/RC
ternal memory. This pin (ALE/PROG) is also the
program pulse input during EPROM programming for
the 87C51RX.
In normal operation ALE is emitted at a constant
rate of (/6 the oscillator frequency, and may be used
for external timing or clocking purposes. Note, however, that one ALE pulse is skipped during each access to external Data Memory.
If desired, ALE operation can be disabled by setting
bit 0 of SFR location 8EH. With this bit set, the pin is
weakly pulled high. However, the ALE disable feature will be suspended during a MOVX or MOVC instruction, idle mode, power down mode and ICE
mode. The ALE disable feature will be terminated by
reset. When the ALE disable feature is suspended or
terminated, the ALE pin will no longer be pulled up
weakly. Setting the ALE-disable bit has no affect if
the microcontroller is in external execution mode.
Throughout the remainder of this data sheet, ALE
will refer to the signal coming out of the ALE/PROG
pin, and the pin will be referred to as the ALE/PROG
pin.
PSEN: Program Store Enable is the read strobe to
external Program Memory.
When the 8XC51RX is executing code from external
Program Memory, PSEN is activated twice each
machine cycle, except that two PSEN activations
are skipped during each access to external Data
Memory.
EA/VPP: External Access enable. EA must be
strapped to VSS in order to enable the device to
fetch code from external Program Memory locations
0000H to 0FFFFH. Note, however, that if any of the
Lock bits are programmed, EA will be internally
latched on reset.
ured for use as an on-chip oscillator, as shown in
Figure 3. Either a quartz crystal or ceramic resonator
may be used. More detailed information concerning
the use of the on-chip oscillator is available in Application Note AP-155, ‘‘Oscillators for Microcontrollers’’, Order No. 230659.
272659 – 5
C1, C2 e 30 pF g 10 pF for Crystals
For Ceramic Resonators, contact resonator manufacturer.
Figure 3. Oscillator Connections
To drive the device from an external clock source,
XTAL1 should be driven, while XTAL2 floats, as
shown in Figure 4. There are no requirements on the
duty cycle of the external clock signal, since the input to the internal clocking circuitry is through a divide-by-two flip-flop, but minimum and maximum
high and low times specified on the data sheet must
be observed.
An external oscillator may encounter as much as a
100 pF load at XTAL1 when it starts up. This is due
to interaction between the amplifier and its feedback
capacitance. Once the external signal meets the VIL
and VIH specifications the capacitance will not exceed 20 pF.
EA should be strapped to VCC for internal program
executions.
This pin also receives the programming supply voltage (VPP) during EPROM programming.
272659 – 6
Figure 4. External Clock Drive Configuration
XTAL1: Input to the inverting oscillator amplifier.
XTAL2: Output from the inverting oscillator amplifier.
OSCILLATOR CHARACTERISTICS
XTAL1 and XTAL2 are the input and output, respectively, of a inverting amplifier which can be config-
IDLE MODE
The user’s software can invoke the Idle Mode. When
the microcontroller is in this mode, power consumption is reduced. The Special Function Registers and
the onboard RAM retain their values during Idle, but
the processor stops executing instructions. Idle
5
8XC51RA/RB/RC
Table 2. Status of the External Pins during Idle and Power Down
Program
Memory
ALE
PSEN
PORT0
PORT1
PORT2
PORT3
Idle
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
Mode will be exited if the chip is reset or if an enabled interrupt occurs.
POWER DOWN MODE
To save even more power, a Power Down mode 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 until the Power Down mode is terminated.
On the 8XC51RX either a hardware reset or an external interrupt can cause an 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 on-chip RAM to retain their values.
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).
With an external interrupt, INT0 and 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 executed after
RETI will be the one following the instruction that put
the device into Power Down.
DEDICATED HARDWARE WATCHDOG
TIMER (One-Time Enabled with
Reset-Out)
The 8XC51RX contains a dedicated WatchDog Timer (WDT) to allow recovery from software or hard-
ware upset. WDT is disabled upon power-up. To enable the WDT, user must write 1EH and E1H in sequence to WDTRST Special Function Register.
Once the WDT is enabled, the 14-bit counter will
increment every machine cycle. While the oscillator
is running, the WDT will be incrementing and cannot
be disabled. The counter is reset by writing 1EH and
E1H in sequence to the WDTRST. If the counter is
not reset before it reaches 3FFFH (16383D), the
chip will be forced into reset sequence and the WDT
will be disabled as upon power-up. During this reset,
the chip will drive an output Reset-High pulse for the
duration of 96 x TOSC at the RST pin. The duration
of the Reset-High pulse works out to 6.00 ms @
16 MHz.
While in the Idle mode the WDT continues to count.
If the user does not wish to exit the Idle mode with a
reset, then the processor must periodically ‘‘woken
up’’ to service the WDT. In Power Down mode, the
WDT stops counting and holds its current value.
DESIGN CONSIDERATION
# The window on the D87C51RX must be covered
by an opaque label. Otherwise, the DC and AC
characteristics may not be met, and the device
may be functionally impaired.
# 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.
NOTE:
For more detailed information on the reduced power modes refer to current Embedded Microcontrollers and Processors
Handbook Volume I, (Order No. 270645) and Application Note AP-252 (Embedded Applications Handbook, Order No.
270648), ‘‘Designing with the 80C51BH.’’
6
8XC51RA/RB/RC
ONCE MODE
whose operating requirements exceed commercial
standards.
The ONCE (‘‘On-Circuit Emulation’’) Mode facilitates
testing and debugging of systems using the
8XC51RX without the 8XC51RX having to be removed from the circuit. The ONCE Mode is invoked
by:
The EXPRESS program includes the commercial
standard temperature range with burn-in and an extended temperature range with or without burn-in.
1) Pull ALE low while the device is in reset and
PSEN is high;
2) Hold ALE low as RST is deactivated.
While the device is in ONCE Mode, the Port 0 pins
float and the other port pins and ALE and PSEN are
weakly pulled high. The oscillator circuit remains active. While the 8XC51RX 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.
With the commercial standard temperature range,
operational characteristics are guaranteed over the
temperature range of 0§ C to a 70§ C. With the extended temperature range option, operational characteristics are guaranteed over the range of b 40§ C
to a 85§ C.
The optional burn-in is dynamic for a minimum time
of 168 hours at 125§ C with VCC e 6.9V g 0.25V,
following guidelines in MIL-STD-883, Method 1015.
Package types and EXPRESS versions are identified
by a one- or two-letter prefix to the part number. The
prefixes are listed in Table 3.
8XC51RX EXPRESS
The Intel EXPRESS system offers enhancements to
the operational specifications of the MCS 51 family
of microcontrollers. These EXPRESS products are
designed to meet the needs of those applications
For the extended temperature range option, this
data sheet specifies the parameters which deviate
from their commercial temperature range limits.
Table 3. Prefix Identification
Package
Type
Temperature
Range
Burn-In
P
Plastic
Commercial
No
N
PLCC
Commercial
No
S
QFP
Commercial
No
TP
Plastic
Extended
No
TN
PLCC
Extended
No
TS
QFP
Extended
No
LP
Plastic
Extended
Yes
LN
PLCC
Extended
Yes
LS
QFP
Extended
Yes
Prefix
NOTE:
Contact distributor or local sales office to match EXPRESS prefix with proper device.
EXAMPLES:
P80C51RA indicates 80C51RA in a plastic package and specified for commercial temperature range, without burn-in.
TS87C51RC indicates 87C51RC in a QFP package and specified for extended temperature range, without burn-in.
7
8XC51RA/RB/RC
ABSOLUTE MAXIMUM RATINGS*
NOTICE: This data sheet contains information on
products in the sampling and initial production phases
of development. The specifications are subject to
change without notice. Verify with your local Intel
Sales office that you have the latest data sheet before finalizing a design.
Ambient Temperature Under Bias À b 40§ C to a 85§ C
Storage Temperature ÀÀÀÀÀÀÀÀÀÀ b 65§ C to a 150§ C
Voltage on EA/VPP Pin to VSS ÀÀÀÀÀÀÀ0V to a 13.0V
Voltage on Any Other Pin to VSS ÀÀ b 0.5V to a 6.5V
IOL Per I/O Pin ÀÀÀÀÀÀÀÀÀÀÀÀÀÀÀÀÀÀÀÀÀÀÀÀÀÀÀ15 mA
Power DissipationÀÀÀÀÀÀÀÀÀÀÀÀÀÀÀÀÀÀÀÀÀÀÀÀÀÀ1.5W
(based on PACKAGE heat transfer limitations, not
device power consumption)
*WARNING: Stressing the device beyond the ‘‘Absolute
Maximum Ratings’’ may cause permanent damage.
These are stress ratings only. Operation beyond the
‘‘Operating Conditions’’ is not recommended and extended exposure beyond the ‘‘Operating Conditions’’
may affect device reliability.
OPERATING CONDITIONS
Symbol
TA
VCC
fOSC
Description
Min
Max
Units
Ambient Temperature Under Bias
Commercial
Express
0
b 40
a 70
a 85
§C
§C
Supply Voltage
All Others
8XC51RX-24
4.0
4.5
6.0
5.5
V
V
0scillator Frequency
8XC51RX
8XC51RX-1
8XC51RX-20
8XC51RX-24
3.5
3.5
3.5
3.5
12
16
20
24
MHz
MHz
MHz
MHz
DC CHARACTERISTICS
(Over Operating Conditions)
All parameter values apply to all devices unless otherwise indicated.
Symbol
Parameter
Min
Typ
(Note 4)
Max
Unit
Test Conditions
VIL
Input Low Voltage
b 0.5
0.2 VCC b 0.1
V
VIL1
Input Low Voltage EA
0
0.2 VCC b 0.3
V
VIH
Input High Voltage
(Except XTAL1, RST)
0.2 VCC a 0.9
VCC a 0.5
V
VIH1
Input High Voltage
(XTAL1, RST)
0.7 VCC
VCC a 0.5
V
VOL
Output Low Voltage (Note 5)
(Ports 1, 2 and 3)
0.3
V
IOL e 100 mA (Note 1)
0.45
V
IOL e 1.6 mA (Note 1)
1.0
V
0.3
V
IOL e 3.5 mA (Note 1)
IOL e 200 mA (Note 1)
0.45
V
IOL e 3.2 mA (Note 1)
V
VOL1
Output Low Voltage (Note 5)
(Port 0, ALE, PSEN)
1.0
VOH
8
Output High Voltage
(Ports 1, 2 and 3, ALE, PSEN)
VCC b 0.3
V
IOL e 7.0 mA (Note 1)
IOH e b 10 mA
VCC b 0.7
V
IOH e b 30 mA
VCC b 1.5
V
IOH e b 60 mA
8XC51RA/RB/RC
DC CHARACTERISTICS
(Over Operating Conditions) (Continued)
All parameter values apply to all devices unless otherwise indicated.
Symbol
VOH1
VOH2
IIL
Parameter
Output High Voltage
(Port 0 in External Bus Mode)
Output High Voltage
(RST)
Min
Typ
(Note 4)
Max
Unit
Test Conditions
VCC b 0.3
V
IOH e b 200 mA
VCC b 0.7
V
IOH e b 3.2 mA
VCC b 1.5
V
IOH e b 7.0 mA
0.5 VCC
V
IOH e b 800 mA
0.75 VCC
V
IOH e b 300 mA
0.9 VCC
V
IOH e b 80 mA
Logical 0 Input Current
(Ports 1, 2 and 3)
b 50
mA
VIN e 0.45V
ILI
Input leakage Current (Port 0)
g 10
mA
VIN e VIL or VIH
ITL
Logical 1 to 0 Transition Current
(Ports 1, 2 and 3)
Commercial
Express
b 675
b 775
mA
mA
VIN e 2V
225
KX
RRST
RST Pulldown Resistor
CIO
Pin Capacitance
ICC
Power Supply Current:
Active Mode
at 12 MHz (Figure 5)
at 16 MHz
at 20 MHz
at 24 MHz
Idle Mode
at 12 MHz (Figure 5)
at 16 MHz
at 20 MHz
at 24 MHz
Power Down Mode
40
10
pF
@1
MHz, 25§ C
(Note 3)
15
30
38
47
56
mA
mA
mA
mA
5
7.5
9.5
11.5
13.5
75
mA
mA
mA
mA
mA
5
NOTES:
1. Capacitive loading on Ports 0 and 2 may cause noise pulses above 0.4V to be superimposed on the VOLs of ALE and
Ports 1, 2 and 3. The noise is due to external bus capacitance discharging into the Port 0 and Port 2 pins when these pins
change from 1 to 0. In applications where capacitive loading exceeds 100 pF, the noise pulses on these signals may exceed
0.8V. It may be desirable to qualify ALE or other signals with a Schmitt Triggers, or CMOS-level input logic.
2. Capacitive loading on Ports 0 and 2 cause the VOH on ALE and PSEN to drop below the 0.9 VCC specification when the
address lines are stabilizing.
3. See Figures 6–9 for test conditions. Minimum VCC for Power Down is 2V.
4. Typicals are based on a limited number of samples and are not guaranteed. The values listed are at room temperature
and 5V.
5. Under steady state (non-transient) conditions, IOL must be externally limited as follows:
10mA
Maximum IOL per port pin:
Maximum IOL per 8-bit portÐ
Port 0:
26 mA
Ports 1, 2 and 3:
15 mA
71 mA
Maximum total IOL for all output pins:
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
8XC51RA/RB/RC
272659 – 7
ICC Max at other frequencies is given by:
Active Mode
ICC Max e 2.2 c Freq a 3.1
Idle Mode
ICC Max e 0.5 c Freq a 1.5
Where Freq is in MHz, ICC Max is given in mA.
Figure 5. ICC vs Frequency
272659 – 8
All other pins disconnected
TCLCH e TCHCL e 5 ns
Figure 6. ICC Test Condition, Active
Mode
272659 – 9
All other pins disconnected
TCLCH e TCHCL e 5 ns
Figure 7. ICC Test Condition Idle Mode
272659 – 10
All other pins disconnected
Figure 8. ICC Test Condition, Power Down Mode
VCC e 2.0V to 6.0V
272659 – 11
Figure 9. Clock Signal Waveform for ICC Tests in Active and Idle Modes. TCLCH e TCHCL e 5 ns
10
8XC51RA/RB/RC
L: Logic level LOW, or ALE
EXPLANATION OF THE AC SYMBOLS
P: PSEN
Each timing symbol has 5 characters. The first character is always a ‘T’ (stands for time). The other
characters, depending on their positions, stand for
the name of a signal or the logical status of that
signal. The following is a list of all the characters and
what they stand for.
Q: Output Data
R: RD signal
T: Time
V: Valid
W: WR signal
X: No longer a valid logic level
Z: Float
A: Address
C: Clock
D: Input Data
H: Logic level HIGH
For example,
I: Instruction (program memory contents)
TAVLL e Time from Address Valid to ALE Low
TLLPL e Time from ALE Low to PSEN Low
AC CHARACTERISTICS
(Over Operating Conditions, Load Capacitance for Port 0, ALE/PROG and
PSEN e 100 pF, Load Capacitance for All Other Outputs e 80 pF)
EXTERNAL MEMORY CHARACTERISTICS
All parameter values apply to all devices unless otherwise indicated. In this table, 8XC51RX refers to
8XC51RX and 8XC51RX-1. 8XC51RX-24 refers to 8XC51RX-20 and 8XC51RX-24.
Symbol
1/TCLCL
Description
12 MHz
Oscillator
20 MHz
Oscillator
24 MHz
Oscillator
Min
Min
Min
Max
Max
Max
Oscillator Frequency
8XC51RX
8XC51RX-1
8XC51RX-20
8XC51RX-24
Variable
Oscillator
Units
Min
Max
3.5
3.5
3.5
3.5
12
16
20
24
MHz
MHz
MHz
MHz
TLHLL
ALE Pulse Width
127
60
43
2 TCLCL b 40
ns
TAVLL
Address Valid to
ALE Low
43
10
12
TCLCL b 40
ns
TLLAX
Address Hold After
ALE Low
53
20
12
TCLCL b 30
ns
TLLIV
ALE Low to Valid
Instruction In
8XC51RX
8XC51RX-24
234
125
4 TCLCL b 100
4 TCLCL b 75
91
ns
ns
TLLPL
ALE Low to PSEN
Low
53
20
12
TCLCL b 30
ns
TPLPH
PSEN Pulse Width
205
105
80
3 TCLCL b 45
ns
TPLIV
PSEN Low to Valid
Instruction In
8XC51RX
8XC51RX-24
TPXIX
Input Instruction
Hold After PSEN
145
60
0
0
3 TCLCL b 105
3 TCLCL b 90
35
0
0
ns
ns
ns
11
8XC51RA/RB/RC
EXTERNAL MEMORY CHARACTERISTICS (Continued)
All parameter values apply to all devices unless otherwise indicated.
Symbol
TPXIZ
Description
12 MHz
Oscillator
20 MHz
Oscillator
24 MHz
Oscillator
Min
Min
Min
Input Instruction Float After
PSEN
8XC51RX
8XC51RX-24
Max
Max
Max
Variable
Oscillator
Min
59
30
21
TCLCLb25
TCLCLb20
ns
ns
5 TCLCLb105
ns
10
ns
TAVIV
Address to Valid Instruction
In
312
145
103
TPLAZ
PSEN Low to Address Float
10
10
10
TRLRH
RD Pulse Width
400
200
150
6 TCLCLb100
TWLWH
WR Pulse Width
400
200
150
6 TCLCLb100
TRLDV
RD Low to Valid Data In
8XC51RX
8XC51RX-24
252
155
TRHDX
Data Hold After RD
TRHDZ
Data Float After RD
107
TLLDV
ALE Low to Valid Data In
8XC51RX
8XC51RX-24
517
Address to Valid Data In
8XC51RX
8XC51RX-24
585
TAVDV
0
TLLWL
ALE Low to RD or WR Low
200
TAVWL
Address Valid to WR Low
8XC51RX
8XC51RX-24
203
TQVWX
TWHQX
TQVWH
Data Valid before WR
8XC51RX
8XC51RX-20
8XC51RX-24
Data Hold after WR
8XC51RX
8XC51RX-20
8XC51RX-24
Data Valid to WR High
8XC51RX
8XC51RX-24
TRLAZ
RD Low to Address Float
TWHLH
RD or WR High to ALE High
8XC51RX
8XC51RX-24
12
0
300
100
0
ns
ns
ns
2 TCLCLb60
ns
310
243
8 TCLCLb150
8 TCLCLb90
ns
ns
360
285
9 TCLCLb165
9 TCLCLb90
ns
ns
3 TCLCL a 50
ns
200
75
175
4 TCLCLb130
4 TCLCLb90
ns
ns
12
TCLCLb50
TCLCLb35
TCLCLb30
ns
ns
ns
7
TCLCLb50
TCLCLb40
TCLCLb30
ns
ns
ns
222
7 TCLCLb150
7 TCLCLb70
ns
ns
10
433
280
3 TCLCLb50
77
33
0
10
ns
23
15
123
ns
40
33
43
5 TCLCLb165
5 TCLCLb95
113
0
110
0
Units
Max
0
90
12
71
TCLCLb40
TCLCLb30
0
ns
TCLCL a 40
TCLCL a 30
ns
8XC51RA/RB/RC
EXTERNAL PROGRAM MEMORY READ CYCLE
272659 – 12
EXTERNAL DATA MEMORY READ CYCLE
272659 – 13
EXTERNAL DATA MEMORY WRITE CYCLE
272659 – 14
13
8XC51RA/RB/RC
SERIAL PORT TIMING - SHIFT REGISTER MODE
Test Conditions: Over Operating Conditions; Load Capacitance e 80 pF
Symbol
Parameter
TXLXL
Serial Port Clock
Cycle Time
TQVXH
Output Data
Setup to Clock
Rising Edge
TXHQX
Output Data
Hold after Clock
Rising Edge
8XC51RX
8XC51RX-24
TXHDX
Input Data Hold
After Clock
Rising Edge
TXHDV
Clock Rising
Edge to Input
Data Valid
12 MHz
Oscillator
20 MHz
Oscillator
24 MHz
Oscillator
Min Max
Min
Min
1
0.600
700
367
Max
Max
0.500
284
50
0
700
Variable
Oscillator
Min
Units
Max
12 TCLCL
ms
10 TCLCL b 133
ns
50
34
2 TCLCL b 117
2 TCLCL b 50
ns
ns
0
0
0
ns
367
284
10 TCLCL b 133
ns
SHIFT REGISTER MODE TIMING WAVEFORMS
272659 – 15
14
8XC51RA/RB/RC
EXTERNAL CLOCK DRIVE
Symbol
Parameter
Min
Max
1/TCLCL
Oscillator Frequency
8XC51RX
8XC51RX-1
8XC51RX-20
8XC51RX-24
3.5
3.5
3.5
3.5
12
16
20
24
Units
MHz
TCHCX
High Time
0.35 TOSC
0.65 TOSC
ns
TCLCX
Low Time
0.35 TOSC
0.65 TOSC
ns
TCLCH
Rise Time
8XC51RX
8XC51RX-24
20
10
ns
ns
Fall Time20
8XC51RX
8XC51RX-24
20
10
ns
ns
ns
TCHCL
EXTERNAL CLOCK DRIVE WAVEFORM
272659 – 16
AC TESTING INPUT, OUTPUT WAVEFORMS
272659 – 17
AC Inputs during testing are driven at VCC b 0.5V 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’’.
FLOAT WAVEFORMS
272659 – 18
For timing purposes a port pin is no longer floating when a
100 mV change from load voltage occurs, and begins to float
when a 100 mV change from the loaded VOH/VOL level occurs.
IOL/IOH e g 20 mA.
15
8XC51RA/RB/RC
PROGRAMMING THE EPROM
DEFINITION OF TERMS
The part must be running with a 4 MHz to 6 MHz
oscillator. The address of an EPROM location to be
programmed is applied to address lines while the
code byte to be programmed in that location is applied to data lines. Control and program signals must
be held at the levels indicated in Table 4. Normally
EA/VPP is held at logic high until just before ALE/
PROG is to be pulsed. The EA/VPP is raised to VPP,
ALE/PROG is pulsed low and then EA/VPP is returned to a high (also refer to timing diagrams).
ADDRESS LINES: P1.0 – P1.7, P2.0 – P2.5 respectively for A0 – A13.
DATA LINES: P0.0 – P0.7 for D0 – D7.
CONTROL SIGNALS: RST, PSEN, P2.6, P2.7, P3.3,
P3.6, P3.7
PROGRAM SIGNALS: ALE/PROG, EA/VPP
NOTES:
# Exceeding the VPP maximum for any amount of
time could damage the device permanently. The
VPP source must be well regulated and free of
glitches.
Table 4. EPROM Programming Modes
Mode
Program Code Data
RST
PSEN
ALE/
PROG
EA/
VPP
P2.6
P2.7
P3.3
P3.6
P3.7
H
L
ß
12.75V
L
H
H
H
H
Verify Code Data
H
L
H
H
L
L
L
H
H
Program Encryption
Array Address 0–3FH
H
L
ß
12.75V
L
H
H
L
H
Program Lock
Bits
Bit 1
H
L
ß
12.75V
H
H
H
H
H
Bit 2
H
L
ß
12.75V
H
H
H
L
L
Bit 3
H
L
ß
12.75V
H
L
H
H
L
H
L
H
H
L
L
L
L
L
Read Signature Byte
16
8XC51RA/RB/RC
272659 – 19
*See Table 4 for proper input on these pins
Figure 10. Programming the EPROM
PROGRAMMING ALGORITHM
Refer to Table 4 and Figures 10 and 11 for address,
data, and control signals set up. To program the
87C51RX the following sequence must be exercised.
1. Input the valid address on the address lines.
2. Input the appropriate data byte on the data
lines.
3. Activate the correct combination of control signals.
4. Raise EA/VPP from VCC to 12.75V g 0.25V.
5. Pulse ALE/PROG 5 times for the EPROM array, and 25 times for the encryption table and
the lock bits.
Repeat 1 through 5 changing the address and data
for the entire array or until the end of the object file is
reached.
PROGRAM VERIFY
Program verify may be done after each byte or block
of bytes is programmed. In either case a complete
verify of the programmed array will ensure reliable
programming of the 87C51RX.
The lock bits cannot be directly verified. Verification
of the lock bits is done by observing that their features are enabled.
272659 – 20
Figure 11. Programming Signal’s Waveforms
17
8XC51RA/RB/RC
ROM and EPROM Lock System
The program lock system, when programmed, protects the onboard program against software piracy.
The 83C51RX has a one-level program lock system
and a 64-byte encryption table. See line 2 of Table
5. If program protection is desired. the user submits
the encryption table with their code. and both the
lock-bit and encryption array are programmed by the
factory. The encryption array is not available without
the lock bit. For the lock bit to be programmed, the
user must submit an encryption table.
The 87C51RX has a 3-level program lock system
and a 64-byte encryption array. Since this is an
EPROM device, all locations are user-programmable. See Table 5.
If any program lock bits were programmed, erasing
the EPROM will not erase the program lock bits and
programming of the EPROM is disabled.
Reading the Signature Bytes
The 8XC51RX has 3 signature bytes in locations
30H, 31H, and 60H. To read these bytes follow the
procedure for EPROM verify, but activate the control
lines provided in Table 4 for Read Signature Byte.
Location
Device
Contents
30H
All
89H
31H
All
58H
60H
87C51RC
C2H
87C51RB
C1H
Encryption Array
87C51RA
C0H
Within the EPROM array are 64 bytes of Encryption
Array that are initially unprogrammed (all 1’s). Every
time that a byte is addressed during a verify, 6 address lines are used to select a byte of the Encryption Array. This byte is then exclusive-NOR’ed
(XNOR) with the code byte, creating an Encryption
Verify byte. The algorithm, with the array in the unprogrammed state (all 1’s), will return the code in its
original, unmodified form. For programming the Encryption Array, refer to Table 4 (Programming the
EPROM).
83C51RC
42H/C2H
83C51RB
41H/C1H
83C51RA
40H/C0H
When using the encryption array, one important factor needs to be considered. If a code byte has the
value 0FFH, verifying the byte will produce the encryption byte value. If a large block ( l 64 bytes) of
code is left unprogrammed, a verification routine will
display the contents of the encryption array. For this
reason all unused code bytes should be programmed with some value other than 0FFH, and not
all of them the same value. This will ensure maximum program protection.
Program Lock Bits
The 87C51RX has 3 programmable lock bits that
when programmed according to Table 5 will provide
different levels of protection for the on-chip code
and data.
18
Erasure Characteristics
(Windowed Packages Only)
Erasure of the EPROM begins to occur when the
chip is exposed to light with wavelength shorter than
approximately 4,000 Angstroms. Since sunlight and
fluorescent lighting have wavelengths in this range,
exposure to these light sources over an extended
time (about 1 week in sunlight, or 3 years in roomlevel fluorescent lighting) could cause inadvertent
erasure. If an application subjects the device to this
type of exposure, it is suggested that an opaque label be placed over the window.
The recommended erasure procedure is exposure
to ultraviolet light (at 2537 Angstroms) to an integrated dose of at least 15 W-sec/cm2. Exposing the
EPROM to an ultraviolet lamp of 12,000 mW/cm2
rating for 30 minutes, at a distance of about 1 inch,
should be sufficient.
Erasure leaves all the EPROM Cells in a 1’s state.
8XC51RA/RB/RC
Table 5. Program Lock Bits and the Features
Program Lock Bits
Protection Type
LB1
LB2
LB3
1
U
U
U
No Program Lock features enabled. (Code verify will still be encrypted by the
Encryption Array if programmed.)
2
P
U
U
MOVC instructions executed from external program memory are disabled from
fetching code bytes from internal memory, EA is sampled and latched on
Reset, and further programming of the EPROM is disabled.
3
P
P
U
Same as 2, also verify is disabled.
4
P
P
P
Same as 3, also external execution is disabled.
NOTE:
Any other combination of the lock bits is not defined.
EPROM PROGRAMMING AND VERIFICATION CHARACTERISTICS
(TA e 21§ C to 27§ C; VCC e 5V g 20%; VSS e 0V)
Symbol
Parameter
Min
Max
VPP
Programming Supply Voltage
12.5
13.0
V
IPP
Programming Supply Current
75
mA
6
MHz
4
Units
1/TCLCL
Oscillator Frequency
TAVGL
Address Setup to PROG Low
TGHAX
Address Hold after PROG
48TCLCL
TDVGL
Data Setup to PROG Low
48TCLCL
TGHDX
Data Hold after PROG
48TCLCL
TEHSH
(Enable) High to VPP
48TCLCL
TSHGL
VPP Setup to PROG Low
10
ms
TGHSL
VPP Hold after PROG
10
ms
TGLGH
PROG Width
90
TAVQV
Address to Data Valid
TELQV
ENABLE Low to Data Valid
TEHQZ
Data Float after ENABLE
0
TGHGL
PROG High to PROG Low
10
48TCLCL
110
ms
48TCLCL
48TCLCL
48TCLCL
ms
19
8XC51RA/RB/RC
EPROM PROGRAMMING AND VERIFICATION WAVEFORMS
272659 – 21
*5 pulses for the EPROM array, 25 pulses for the encryption table and lock bits.
Thermal Impedance
DATA SHEET REVISION HISTORY
All thermal impedance data is approximate for static
air conditions at 1W of power dissipation. Values will
change depending on operating conditions and applications. See the Intel Packaging Handbook (Order
Number 240800) for a description of Intel’s thermal
impedance test methodology.
Data sheets are changed as new device information
becomes available. Verify with your local Intel sales
office that you have the latest version before finalizing a design or ordering devices.
Package
iJA
iJC
Device
P
N
S
45§ C/W
46§ C/W
87§ C/W
96§ C/W
90§ C/W
16§ C/W
16§ C/W
18§ C/W
24§ C/W
22§ C/W
All
All
51RA
51RB
51RC
The following differences exist between this datasheet (272659-002) and the previous version
(272659-001):
1. ADVANCE INFORMATION datasheet replaces
PRODUCT PREVIEW datasheet.
2. ITL (Commercial) changed from b 650 mA to
b 675 mA.
3. ITL (Express) changed from b 750 mA to
b 775 mA.
4. 8XC51RX-24, VCC changed from 5V g 20% to
5V g 10%.
5. Remove all CERDIP package types (prefix D, TD,
LD).
INTEL CORPORATION, 2200 Mission College Blvd., Santa Clara, CA 95052; Tel. (408) 765-8080
INTEL CORPORATION (U.K.) Ltd., Swindon, United Kingdom; Tel. (0793) 696 000
INTEL JAPAN k.k., Ibaraki-ken; Tel. 029747-8511