SAB80C537-N Infineon Technologies, SAB80C537-N Datasheet - Page 42
Manufacturer Part Number
IC MIRCROCONTROLLER 8BIT 84PLCC
Specifications of SAB80C537-N
POR, PWM, WDT
Number Of I /o
Program Memory Type
256 x 8
Voltage - Supply (vcc/vdd)
4.5 V ~ 5.5 V
0°C ~ 70°C
Package / Case
Lead Free Status / RoHS Status
Lead free / RoHS Compliant
Serial Interface 1
Serial interface 1 can operate in two asynchronous modes:
Variable Baud Rates for Serial Interface 1
Variable baud rates for modes A and B of serial interface 1 can be derived from a dedicated
baud rate generator.
The baud rate clock (baud rate =
running timer with programmable reload register. SAB 80C517 devices with stepping code
"CA" or later provide a 10-bit free running timer for baud rate generation.
Mode A, B baud rate =
The SAB 80C517 offers two enhanced fail safe mechanisms, which allow an automatic recov-
ery from hardware failure or software upset:
– programmable watchdog timer (WDT), variable from 512 ms up to about 1.1 s time out
– oscillator watchdog (OWD), monitors the on-chip oscillator and forces the microcontroller to
Programmable Watchdog Timer
The WDT can be activated by hardware or software.
Hardware initialization is done when pin PE/SWD (Pin 4) is held high during RESET. The
SAB 80C517 then starts program execution with the WDT running. Pin PE/SWD doesn’t allow
dynamic switching of the WDT.
Software initialization is done by setting bit SWDT. A refresh of the watchdog timer is done by
setting bits WDT and SWDT consecutively.
A block diagram of the watchdog timer is shown in figure 11.
When a watchdog timer reset occurs, the watchdog timer keeps on running, but a status flag
WDTS is set. This flag can also be manipulated by software.
period @12 MHz. Upward compatible to SAB 80515 watchdog.
go into reset state, in case the on-chip oscillator fails.
9-bit UART, variable baud rate.
11 bits are transmitted (through TXD0) or received (through RXD0): a start bit (0),
8 data bits (LSB first), a programmable 9th, and a stop bit (1). On transmission, the
the parity bit (P in the PSW) could be moved into TB81 or a second stop bit by
setting TB81 to 1. On reception the 9
register S1CON, while the stop bit is ignored.
8-bit UART, variable baud rate.
10 bits are transmitted (through TXD1) or received (through RXD1): a start bit (0),
8 data bits (LSB first), and a stop bit (1). On reception, the stop bit goes into RB81
in special function register S1CON.
data bit (TB81 in S1CON) can be assigned to the value of 0 or 1. For example,
baud rate clock
) is generated by a 8-bit free
data bit goes into RB81 in special function