HONEYWELL HT83C51DB

HTMOSTM High Temperature Products
Preliminary
HT83C51
HIGH TEMPERATURE 83C51
MICROCONTROLLER
FEATURES
• HTMOS Specified Over -55 to +225°C
• Hermetic 40-Pin Ceramic DIP
• 8-bit CPU Optimized For 5 Volt Control Applications
• 64K External Data Memory Address Space
• Four 8-bit Bidirectional Parallel Ports
• 256 Bytes Internal Data Memory
• Three 16-bit Timer/Counters with One Up/Down
Timer/Counter and Clock Out
• 8K Byte Mask ROM
• Programmable Counter Array with:
– Capture/Compare
– Software Timer with Watchdog Capability
– High Speed Output
– Pulse Width Modulator
• On-Chip Oscillator
• MCS-51Compatible Instruction Set
APPLICATIONS
• Down-Hole Oil Well
• Interrupt Structure with Seven Sources and
Four Priority Levels
• Half Duplex Programmable Serial Port with:
– Framing Error Detection
– Automatic Address Recognition
• 64K External Program Memory Address Space
• Avionics
• Turbine Engine Control
• Industrial Process Control
• Nuclear Reactor
• Electric Power Conversion
• Heavy Duty Internal Combustion Engines
GENERAL DESCRIPTION
The HT83C51 is a monolithic 8-bit microcontroller that is
pin equivalent to the Intel 8XC51FC microcontroller. Fabricated with Honeywell’s dielectrically isolated high-temperature (HTMOS™) process, it is designed specifically for
severe high-temperature applications such as down-hole
oil well, aerospace, turbine engine and industrial control.
and a hierarchical interrupt structure. Software selectable
idle is included for reduced power. The HT83C51 varies
from the standard 83C51FC, in that it supports half-duplex
serial communication, and has 8K Bytes of Mask programmable ROM. The device is available in a standard pinout
DIP, with optional packages considered.
The HT83C51 uses the standard MCS-51 instruction set
which is optimized for control applications. Pin-for-pin
equivalent to the MCS-51 series product, it is compatible
with all known development environments. Key features
include the programmable counter array, watch dog timer,
enhanced serial port for multi-processor communication
These microcontrollers provide guaranteed performance
supporting operating frequencies in excess of 16 MHz
over the full -55 to +225°C temperature range. Typically,
parts will operate up to +300°C for a year, with derated
performance. All parts are burned in at 250°C to eliminate
infant mortality.
Solid State Electronics Center • 12001 State Highway 55, Plymouth, MN 55441 • (800) 323-8295 • http://www.ssec.honeywell.com
HT83C51
RAM Addr.
Register
FUNCTIONAL BLOCK DIAGRAM
P0.0 - P0.7
P2.0 - P2.7
Port O
Drivers
Port 2
Drivers
Port O
Latch
RAM
Port 2
Latch
Program
ROM
Program
Address
Register
B
B
Register
Register
Stack
Pointer
ACC
Buffer
TMP2
TMP1
Special Function
Registers,
Timers,
PCA,
Serial Port
ALU
PSENn
ALE
EAn
RST
Instruction
Register
Microsequencer
PSW
TMP3
Program
Counter
DPTR
Port 3
Latch
Port 1
Latch
Osc.
XTAL1
PC
Incrementer
Port 1
Drivers
Port 3
Drivers
P1.0 - P1.7
P3.0 - P3.7
XTAL2
2
HT83C51
PIN DESCRIPTIONS
VDD: +5V Supply Voltage
loads. When the Port 3 pins have 1’s written to them, they
are pulled high by the internal pullups and can be used as
inputs in this state. As inputs, any pins that are externally
pulled low will source current because of the pullups. In
addition, Port 3 pins have the alternate uses shown in the
table below:
VSS: Circuit Ground
Port 0 (P0.0 - P0.7): Port 0 is an 8-bit bidirectional I/O port.
If external Program and/or Data memory are used, port 0
cannot be used for general purpose I/O. During accesses
to external Program and Data memory Port 0 is used as the
low-order multiplexed address and data bus. In this mode,
Port 0 pins use strong internal pullups when emitting 1’s,
and are TTL compatible. If external Program and Data
memory are not used, Port 0 pins can be used as general
purpose I/O. When the Port pins have 1’s written to them
in I/O mode, the pins are floating and can be driven as
inputs. An external pullup is required to generate logic high
output in I/O mode.
Port Pin
Port 1 (P1.0 - P1.7): Port 1 is an 8-bit bidirectional I/O port
with internal pullups. The output buffers can drive TTL
loads. When the Port 1 pins have 1’s written to them, they
are pulled high by the internal pullups and can be used as
inputs in this state. As inputs, any pins that are externally
pulled low will source current because of the pullups. In
addition, Port 1 pins have the alternate uses shown in the
table below:
Port
Pin
Name
P1.0
T2
P1.1
T2EX
P1.2
ECI
P1.3
CEX0
External I/O for PCA capture/compare Module 0
P1.4
CEX1
External I/O for PCA capture/compare Module 1
P1.5
CEX2
External I/O for PCA capture/compare Module 2
P1.6
CEX3
External I/O for PCA capture/compare Module 3
P1.7
CEX4
External I/O for PCA capture/compare Module 4
Alternate Name Alternate Function
P3.0
RXD
Serial port input
P3.1
TXD
Serial port output
P3.2
INT0n
External interrupt 0
P3.3
INT1n
External interrupt 1
P3.4
T0
External clock input for Timer 0
P3.5
T1
External clock input for Timer 1
P3.6
WRn
External Data Memory write strobe
P3.7
RDn
External Data Memory read strobe
RST: Reset input. A high on this input for 2 or more
oscillator periods while the oscillator is running resets the
device. All ports and Special Function Registers will be
reset to their default conditions. Internal data memory is
undefined after reset. Program execution will begin within
12 oscillator periods (one machine cycle) after the RST
signal is brought low. RST contains an internal pulldown
resistor to allow implementing power-up reset with only an
external capacitor.
Alternate Function
External clock input to timer/ Clock out
Timer/Counter 2 Capture/Reload trigger and
direction control
ALE: Address Latch Enable. The ALE output is a pulse for
latching the low byte of the address during accesses to
external memory. In normal operation the ALE pulse is
output every 6th oscillator cycle and may be used for
external timing or clocking. However, during each access
to external Data Memory (MOVX instruction), one ALE
pulse is skipped. If desired, ALE operation can be disabled
by setting bit 0 of SFR 8EH. When this bit is set, ALE is
active only during a MOVX instruction. Otherwise, the pin
is held low. When ALE is disabled, program execution
must be limited to the internal 8K program ROM.
External count input to PCA
Port 2 (P2.0 - P2.7): Port 2 is an 8-bit bidirectional I/O port
with internal pullups. The output buffers can drive TTL
loads. When the Port 2 pins have 1’s written to them, they
are pulled high by the internal pullups and can be used as
inputs in this state. As inputs, any pins that are externally
pulled low will source current because of the pullups.
PSENn: Program Store Enable. This active low signal is
the read strobe to the external program memory. PSENn
is activated every 6th oscillator cycle except that 2 PSENn
activations are skipped during external data memory
accesses.
Port 2 is used as the high-order address byte during
accesses to external Program Memory and during accesses
to external Data Memory that use 16-bit addresses (i.e.
MOVX @DPTR). It uses strong internal pullups when
emitting 1’s in this mode. During accesses to external Data
Memory that use 8 bit addresses, Port 2 emits the contents
of the P2 SFR.
EAn: External Access Enable. The EAn pin must be
strapped to VSS for the HT51 to fetch code from external
Program Memory locations 0000H to 1FFFH. The EAn pin
must be strapped to VDD for internal program execution
from memory locations 0000H to 1FFFH.
XTAL1: Input to the inverting oscillator amplifier.
Port 3 (P3.0 - P3.7): Port 3 is an 8-bit bidirectional I/O port
with internal pullups. The output buffers can drive TTL
XTAL2: Output from the inverting oscillator amplifier.
3
HT83C51
OSCILLATOR CHARACTERISTICS
The input is XTAL1 and the output is XTAL2 for an inverting
amplifier which can be used as an on-chip oscillator as
shown in Figure 1. Make sure to qualify the crystal or
alternate timing source over the temperature range of the
intended application. If an external clock source such as
the HTOSC is used, XTAL1 should be driven while XTAL2
floats as shown in Figure 2. There are no duty cycle
requirements on the external clock signal, but minimum
and maximum high and low times must be observed.
The other way that Idle mode can be terminated is through
a hardware reset, which can be accomplished by holding
the RST pin high for 4 clock periods while the clock is
running. Exiting Idle mode with a hardware reset will retain
the contents of the on-chip RAM but the values in the SFRs
will be lost and program execution will begin at address 0.
MEMORY
C2
The HT51 has a separate address space for Program and
Data Memory. Internally the HT51 contains 8 Kbytes of
Program Memory and 256 bytes of Data Memory. It can
address up to 64 Kbytes of external Data Memory and 64
Kbytes of external Program Memory.
XTAL 2
C1
XTAL 1
Vss
There are 8 Kbytes of internal program memory in the
HT51. The EAn pin must be tied to Vdd (power) to enable
access to internal program memory locations. When the
EAn pin is tied to Vdd, program fetches to addresses
0000H to 1FFFH will be made to internal program ROM.
Program fetches to addresses 2000H through FFFFH are
to external memory. The EAn pin must be tied to Vss
(ground) to enable access to external program memory
locations 0000H through 1FFFH.
For C1 and C2 values,
contact crystal manufacturer
Figure 1. Oscillator Connections
N/C
External
Oscillator
Signal
XTAL 2
The HT51 implements 256 bytes of internal data RAM. The
upper 128 bytes of this RAM occupy a parallel address
space to the Special Function Registers (SFRs). The CPU
determines if the internal access to an address above 7FH
is to the upper 128 bytes of RAM or to the SFR space by the
addressing mode of the instruction. If direct addressing is
used, the access is to the SFR space. If indirect addressing
is used, the access is to the internal RAM. Stack operations
are indirectly addressed so the upper portion of RAM can
be used as stack space.
XTAL 1
Vss
Figure 2. External Clock Drive Configuration
IDLE MODE
TIMER/COUNTERS
An instruction that sets the PCON.0-bit causes that to be
the last instruction executed prior to going into Idle
mode. In the Idle mode, the internal clock to the CPU is
gated off but not to the Interrupt, Timer, and Serial Port
functions. The PCA can be programmed to either pause
or continue operating during Idle Mode. The CPU status
is completely preserved and all registers maintain their
previous values during Idle Mode. The port pins hold the
logical values that they had at the time the Idle mode
was activated. ALE and PSENn hold at logic high levels.
The HT51 contains three 16-bit timer/counters. Each of
these are made up of two 8-bit registers (THx, TLx where
x = 0, 1, or 2). Each of these three can operate in either
timer or counter mode. In the timer mode, the TLx register
is incremented once every machine cycle (12 oscillator
periods). The count rate is 1/12th of the oscillator frequency.
In counter mode, the register is incremented when a 1 to 0
transition is detected on the alternate function input
corresponding to that timer (Tx where x = 0, 1, or 2). The
maximum rate of count in counter mode that the HT51 can
detect is 1/24th of the oscillator frequency.
Idle mode can be terminated in two ways. Activation of any
enabled interrupt will cause the PCON.0-bit to be cleared
by hardware, terminating Idle mode. The interrupt will be
serviced, and following the RETI instruction execution, the
instruction after the one that caused Idle mode will be
executed. Recovery from Idle mode is 3 oscillator periods
plus 3 instruction cycles.
4
HT83C51
PCA COUNTER /TIMER
will be made immediately after the RST line is brought low,
but the data is not brought into the processor. The memory
access will be repeated on the next machine cycle and
actual processing will begin at that time.
The Programmable Counter Array (PCA) contains a single
16-bit counter/timer made up of the CL and CH registers.
This timer is used by all 5 capture/compare modules. Its
clock input can be programmed to be from one of four
sources. These are the oscillator frequency divided by 12,
the oscillator frequency divided by 4, Timer 0 overflow, and
an external clock input, ECI, on the alternate function of
port pin P1.2.
INSTRUCTION SET
The instruction set for the HT51 is compatible to the Intel
MCS-51 instruction set used on the 8XC51FC.
SERIAL PORT
AC CHARACTERISTICS
The serial port has physically separate receive and transmit
buffers, automatic address recognition and four modes of
operation as shown below.
Mode
0
1
2
3
Description
Baud Rate
8-bit shift register
8-bit UART
9-bit UART
9-bit UART
1/12 times oscillator freq.
variable
1/64 or 1/32 times oscillator freq.
variable
The AC characteristics for the HT51 are shown in the
following tables. Each of the timing symbols has 5 characters. The first character is always a ‘T’ (Time). The other
characters, depending on their positions, stand for the
logical name of a signal or the logical status of that signal.
The following is a list of the characters and what they stand for:
A:
C:
D:
H:
I:
Address
Clock
Data
Logic level HIGH
Instruction
(program memory contents)
L: Logic level LOW, or ALE
level
P: PSENn
INTERRUPTS
There are seven interrupt sources in the HT51. Two are
external interrupts (INT0n, INT1n), three are timer interrupts
(Timer 0, Timer 1, and Timer2), one is a PCA interrupt, and
one is a serial port interrupt as shown below.
PCA interrupt enable
Timer 2 interrupt enable
Q:
R:
T:
V:
W:
X:
OutputData
RDn signal
Time
Valid
WRn signal
No longer a
valid logic
Z: Float
For example, TAVLL = Time from address valid to ALE
low. The characteristics given are over the operating
conditions TA = -55°C to +225°C, VDD = 5V ± 10 %, VSS = 0V.
The load capacitance on Port 0, ALE and PSENn = 100
pF. Load capacitance for all other outputs = 50 pF. Inputs
during AC testing are to be driven at VDD - 0.5V for logic 1
and 0.45 V for logic 0. Timing measurements are to be
made at VIH min for logic 1 and VIL max for logic 0. 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 VOL/VOH level
occurs. Timing diagrams are shown to illustrate the signal
relationships depicted in the tables.
Serial port interrupt enable
Timer 1 interrupt enable
External interrupt 1 enable
Timer 0 interrupt enable
External interrupt 0 enable
RESET
The reset input is the RST pin. A reset is accomplished by
holding the RST pin high for a minimum of 4 clock periods
while the clock is running. The CPU generates an internal
reset from the external signal. The port pins are driven to
the reset state 2 oscillator periods after a valid 1 is detected
on the RST pin.
While RST is high, PSENn is pulled high, ALE is pulled low,
and the port pins are pulled weakly high. All SFRs are reset
to their reset values. The internal Data Memory content is
not affected by reset. In addition, if the HT51 is in Idle or
Power Down mode prior to activation of RST, the HT51 will
be taken out of Idle or Power Down mode by the reset.
The processor will begin operation on the second machine
cycle after the RST line is brought low. A memory access
5
HT83C51
DC CHARACTERISTICS
Symbol Parameter
Min
Max
VSS-0.3
0.8
Unit
Test Conditions (3)
VIL
Input Low Voltage
VIH
Input High Voltage (except XTAL1, RST)
2.0
VDD+0.5
V
VIH1
Input High Voltage (XTAL1, RST)
3.85
VDD+0.5
V
VOL
Output Low Voltage (1, 2)
(Ports 1, 2, and 3)
0.3
V
IOL = 100 µA
0.45
V
IOL = 1.6 mA
1.0
V
IOL = 3.5 mA
0.3
V
IOL = 200 µA
0.45
V
IOL = 3.2 mA
1.0
V
IOL = 7.0 mA
4.2
V
IOH = -10 µA
3.8
V
IOH = -30 µA
3.0
V
IOH = -60 µA
4.2
V
IOH = -200 µA
3.8
V
IOH = -3.2 mA
3.0
V
IOH = -7.0 mA
VOL1
Output Low Voltage (1, 2)
(Port 0, ALE, PSENn)
VOH
Output High Voltage
(Port 1, 2, 3, ALE, PSENn)
VOH1
Output High Voltage (Port 0)
IIL
Logical 0 Input Current(Ports 1, 2, and 3)
-50
µA
VIN = 0.45 V
I LI
Input Leakage Current (Port 0)
±10
µA
0.45 V < Vin < VDD
ITL
Logical 1 to 0 Transition Current(Ports 1, 2, and 3)
-650
µA
VIN = 2 V
RRST
RST Pulldown Resistor
225
KW
CIO
Pin Capacitance
10 typical
pF
@ 1 MHz, 25° C
70
15
mA
mA
16 MHz
16 MHz
IDD
Power Supply Current
10
Operating
Idle
(1) Under steady state (non-transient conditions, IOL must be limited externally as follows:
maximum IOL per port pin
10mA
maximum IOL per 8-bit port
– port 0
26 mA
– port 1,2,3
15 mA
maximum total IOL for all output pins 71 mA
(2) If IOL exceeds the test conditions, VOL may exceed the related specifications.
(3) Pins are not guaranteed to sink current greater than the listed test conditions.
ABSOLUTE MAXIMUM RATINGS (1)
Input Voltage, VDD to VSS ......................... -0.5 V to 7.0 V
Voltage On Any Pin to VSS ............... -0.5 V to VDD+0.3 V
Power Dissipation ............................................. 750 mW
Storage Temperature ............................... -65 to +325°C
Lead Temperature (attachment, 10 sec) .............. 355°C
IOL per Output Pin ............................................... 15 mA
Stresses in excess of those listed above may result in permanent damage. These
are stress ratings only, and operation at these levels is not implied. Frequent or
extended exposure to absolute maximum conditions may effect device reliability.
6
HT83C51
EXTERNAL PROGRAM AND DATA MEMORY CHARATERISTICS
Symbol
Parameter
Min
TCLCL
Clock Period
62.5
1/TCLCL
Oscillator Frequency
TLHLL
ALE Pulse Width
TAVLL
Max
Unit
ns
16
MHz
2 TCLCL-40
ns
Address Valid to ALE Low
TCLCL-40
ns
TLLAX
Address hold after ALE low
TCLCL-30
ns
TLLIV
ALE low to Valid Instruction In
TLLPL
ALE Low to PSENn Low
TPLPH
PSENn Pulse Width
TPLIV
PSENn low to Valid Instruction In
TPXIX
Input Instruction hold after PSENn
TPXIZ
Input Instruction Float After PSENn
TAVIV
4 TCLCL-100
ns
TCLCL-30
ns
3 TCLCL-45
ns
3 TCLCL-105
0
ns
ns
TCLCL-25
ns
Address to Valid Instruction In
5 TCLCL-105
ns
TPLAZ
PSENn Low to Address Float
10
ns
TRLRH
RDn Pulse Width
6 TCLCL-100
ns
TWLWH
WRn Pulse Width
6 TCLCL-100
ns
TRLDV
RDn Low to Valid Data In
TRHDX
Data Hold After RDn
TRHDZ
Data Float After RDn
TLLDV
5 TCLCL-165
0
ns
ns
2 TCLCL-60
ns
ALE Low to Valid Data In
8 TCLCL-150
ns
TAVDV
Address to Valid Data In
9 TCLCL-165
ns
TLLWL
ALE Low to RDn or WRn Low
3 TCLCL+50
ns
TAVWL
Address Valid to WRn Low
TQVWX
3 TCLCL-50
4 TCLCL-130
ns
Data Valid Before WRn
TCLCL-50
ns
TWHQX
Data Hold After WRn
TCLCL-50
ns
TQVWH
Data Valid to WRn High
7 TCLCL-150
ns
TRLAZ
RDn Low to Address Float
TWHLH
RDn or WRn High to ALE High
TCLCL-40
7
0
ns
TCLCL+40
ns
HT83C51
EXTERNAL PROGRAM MEMORY READ CYCLE
TLHLL
ALE
TLLPL
TPLPH
TAVLL
TLLIV
TPLIV
PSENn
TPXIZ
TPLAZ
TPXIX
TLLAX
PORT 0
A0 - A7
TAVIV
PORT 2
INSTR IN
A0 - A7
A8 - A15
A8 - A15
EXTERNAL DATA MEMORY READ CYCLE
ALE
TLHLL
TWHLH
PSENn
TLLDV
TLLWL
TRLRH
RDn
TRLDV
TAVLL
TLLAX
TRHDX
TRLAZ
TRHDZ
PORT 0
DATA IN
A0 - A7 from RI or DPL
A0 - A7 from PCL
INSTR. IN
TAVWL
TAVDV
PORT 2
P2.0 - P2.7 or A8 - A15 from DPH
A8 - A15 from PCH
EXTERNAL DATA MEMORY WRITE CYCLE
ALE
TLHLL
TWHLH
PSENn
TLLWL
TWLWH
WRn
TAVLL
TQVWX
TLLAX
PORT 0
A0 - A7 from RI or DPL
TWHQX
TQVWH
DATA OUT
A0 - A7 from PCL
INSTR. IN
TAVWL
PORT 2
P2.0 - P2.7 or A8 - A15 from DPH
8
A8 - A15 from PCH
HT83C51
SERIAL PORT TIMING CHARACTERISTICS—SHIFT REGISTER MODE (MODE 0)
16 MHz Oscillator
Variable Oscillator
Symbol
Parameter
TXLXL
Serial Port Clock Period
750
12 TCLCL
ns
TQVXH
Output Data Setup to Clock Rising Edge
492
10 TCLCL-133
ns
TXHQX
Output Data Hold after Clock Rising Edge
8
2 TCLCL-117
ns
TXHDX
Input Data Hold after Clock Rising Edge
0
0
ns
TXHDV
Clock Rising Edge to Input Data Valid
Min
Max
492
SERIAL PORT TIMING WAVEFORMS
0
1
2
3
4
5
6
7
8
ALE
TXLXL
CLOCK
TXHQX
TQVXH
OUTPUT
DATA
0
1
(WRITE TO SBUF)
2
3
4
5
6
7
TXHDX
SET TI
TXHDV
INPUT
DATA
VALID
VALID
VALID
VALID
VALID
VALID
VALID
VALID
(CLEAR RI)
SET RI
9
Min
Max
10 TCLCL-133
Unit
ns
HT83C51
PERFORMANCE CURVES OVER TEMPERATURE
40
5.0
4.8
4.6
Output Voltage (V)
Frequency (MHz)
30
20
4.4
4.2
6µA
4.0
3.8
7mA
3.6
10
3.4
3.2
0
-100
0
100
200
3.0
-100
300
70
-55°C
Operating Current (mA)
60
25°C
125°C
50
225°C
40
30
20
10
10
15
200
Output drive vs. temperature
Maximum frequency vs. temperature
5
100
Temperature (C)
Temperature (°C)
0
0
20
25
Frequency (MHz)
Operating current vs. frequency vs. temperature
10
300
HT83C51
PROGRAMMING THE MASK ROM
The HT83C51 has 8K bytes of on-chip mask programmable ROM. The part is usable with or without this memory
space personalised. Once the designer’s code has been
finalized, the ROM information can be transmitted to Honeywell for metal programming of these memory locations.
A non-recurring fee is required to personalize the ROM and
a quantity purchase commitment fulfilled.
5. DC Characteristics
VIL min for the 8XC51FC is -0.5V for all inputs except EAn
which has a VIL min of 0V. The HT51 has a VIL min for all
inputs of Vss-0.3V.
6. Internal Program Memory
DIFFERENCES BETWEEN
INTEL 8XC51FC AND HT83C51
The 8XC51FC contains 32 Kbytes of internal program
ROM (83C51FC) or EPROM (87C51FC). The HT51
contains 8 Kbytes of internal program ROM.
There are a few areas in which the HT51 differs from the
8XC51FC. These differences will be covered in this
appendix. In this discussion, 8XC51FC will be used
generically to refer to all speed grades of the Intel 8XC51FC
family, including the 16MHz 8XC51FC-1.
7. Serial Communications
There is a chance the part will miss hardware interrupts
when performing full-duplex (simultaneous send and
receive) communication or when using the capture or
compare modes in the Programmable Counter Array (PCA).
1. Reset
The 8XC51FC requires the RST input to be held high for at
least 24 oscillator periods to guarantee the reset is completed
in the chip. Also, the port pins are reset asynchronously as
soon as the RST pin is pulled high. On the HT51, all portions
of the chip are reset synchronously when the RST pin has
been high during 2 rising edges of the input clock.
As a result, the HT83C51 supports half-duplex operation.
Full duplex operation is not supported without additional
external hardware. Several acceptable work-around procedures have been identified for the problem associated
with the PCA.
When coming out of reset, the 8XC51FC takes 1 to 2
machine cycles to begin driving ALE and PSENn. The
HT51 will begin driving ALE and PSENn 2 oscillator periods
after the RST is removed but the access during the first
machine cycle after reset is ignored by the processor. The
second cycle will repeat the access and processing will
begin.
PINOUT DIAGRAM
2. Power Off Flag
The Power Off Flag in the PCON register has not been
implemented in the HT51.
3. On Circuit Emulation
The On Circuit Emulation mode of operation in the 8XC51FC
has not been implemented in the HT51.
`4. Operating Conditions
The operating voltage range for the 8XC51FC is 5V ± 20%.
The operating temperature range is 0° to 70°C. On the
HT51, the operating voltage range is 5V ± 10%. The full
speed operating temperature range is -55° to +225°C;
typically, parts will operate up to +300°C for a year, with
derated performance.
11
(T2) P1.0
1
40
Vdd
(T2EX) P1.1
2
39
P0.0 (AD0)
(ECI) P1.2
3
38
P0.1 (AD1)
(CEXO) P1.3
4
37
P0.2 (AD2)
(CEX1) P1.4
5
36
P0.3 (AD3)
(CEX2) P1.5
6
35
P0.4 (AD4)
(CEX3) P1.6
7
34
P0.5 (AD5)
(CEX4) P1.7
8
33
P0.6 (AD6)
RST
9
32
P0.7 (AD7)
31
EAn
30
ALE
(RXD) P3.0
10
(TXD) P3.1
11
(INT0n) P3.2
12
29
PSENn
(INT1n) P3.3
13
28
P2.7 (A15)
(T0) P3.4
14
27
P2.6 (A14)
(T1) P3.5
15
26
P2.5 (A13)
(WRn) P3.6
16
25
P2.4 (A12)
(RDn) 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)
HT51
HT83C51
40-LEAD PACKAGE DETAIL
C
D
All dimensions in inches
Right
Reading
on Lid
Ceramic 1
Body
A
E
Kovar
Lid [3]
S2
Q
L
b2
eA
A
b
b2
C
D
E
e
eA
L
Q
S1
S2
0.175 (max)
0.018 ± 0.002
0.050 typ
0.010 ± 0.002
2.000 ±0.020
0.594 ± 0.010
0.100 ±0.005
0.600 ± 0.010
0.125 to 0.175
0.050 ± 0.010
0.005 (min)
0.005 (min)
S1
b
(width)
e
(pitch)
THERMAL CHARACTERISTICS
Assumes static air convection
θjc ................................... 0.9°C/W
θja .................................. 32.8°C/W
ORDERING INFORMATION
HT83C51DC
D - Indicates package type*
D = Standard DIP
C - Indicates screening level
B = High Temperature Class B
C = Commercial
*For packaging options, call Honeywell
To learn more about Honeywell Solid State Electronics Center,
visit our web site at http://www.ssec.honeywell.com
Honeywell reserves the right to make changes to any products or technology herein to improve reliability, function or design. Honeywell does not assume any liability
arising out of the application or use of any product or circuit described herein; neither does it convey any license under its patent rights nor the rights of others.
900141 Rev. B
4-98
Helping You Control Your World