HT83C51 Honeywell Microelectronics & Precision Sensors, HT83C51 Datasheet - Page 11

• Manufacturer Part Number: HT83C51
• Description: IC MICROCONTROLLER 8K 40-DIP
• Manufacturer: Honeywell Microelectronics & Precision Sensors
• Series: HTMOS™r

Specifications of HT83C51

• Core Processor: MCS 51
• Core Size: 8-Bit
• Speed: 16MHz
• Connectivity: EBI/EMI, UART/USART
• Peripherals: PWM, WDT
• Number Of I /o: 32
• Program Memory Size: 8KB (8K x 8)
• Program Memory Type: Mask ROM
• Ram Size: 256 x 8
• Voltage - Supply (vcc/vdd): 4.5 V ~ 5.5 V
• Oscillator Type: Internal
• Operating Temperature: -55°C ~ 225°C
• Package / Case: 40-CDIP (0.600", 15.24mm)
• Lead Free Status / RoHS Status: Contains lead / RoHS non-compliant
• Eeprom Size: -
• Data Converters: -

The HT83C51 has 8K bytes of on-chip mask program-
mable 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 Hon-
eywell for metal programming of these memory locations.
A non-recurring fee is required to personalize the ROM and
a quantity purchase commitment fulfilled.
PROGRAMMING THE MASK 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.
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.
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.
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
speed operating temperature range is -55 to +225 C;
typically, parts will operate up to +300 C for a year, with
derated performance.
DIFFERENCES BETWEEN
INTEL 8XC51FC AND HT83C51
10%. The full
11
PINOUT DIAGRAM
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
The 8XC51FC contains 32 Kbytes of internal program
ROM (83C51FC) or EPROM (87C51FC). The HT51
contains 8 Kbytes of internal program ROM.
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).
As a result, the HT83C51 supports half-duplex operation.
Full duplex operation is not supported without additional
external hardware. Several acceptable work-around pro-
cedures have been identified for the problem associated
with the PCA.
(CEXO) P1.3
(INT0n) P3.2
(INT1n) P3.3
(CEX1) P1.4
(CEX2) P1.5
(CEX3) P1.6
(CEX4) P1.7
(T2EX) P1.1
(WRn) P3.6
(RXD) P3.0
(TXD) P3.1
(RDn) P3.7
(ECI) P1.2
(T2) P1.0
(T0) P3.4
(T1) P3.5
XTAL2
XTAL1
RST
Vss
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
HT51
HT83C51
40
39
38
37
36
35
34
33
32
31
30
29
28
27
26
25
24
23
22
21
Vdd
P0.0 (AD0)
P0.1 (AD1)
P0.2 (AD2)
P0.3 (AD3)
P0.4 (AD4)
P0.5 (AD5)
P0.6 (AD6)
P0.7 (AD7)
EAn
ALE
PSENn
P2.7 (A15)
P2.6 (A14)
P2.5 (A13)
P2.4 (A12)
P2.3 (A11)
P2.2 (A10)
P2.1 (A9)
P2.0 (A8)