SAB80C517A-N18 Siemens Semiconductor Group, SAB80C517A-N18 Datasheet - Page 56

• Manufacturer Part Number: SAB80C517A-N18
• Description: 8-Bit CMOS Single-Chip Microcontroller
• Manufacturer: Siemens Semiconductor Group

Serial Interface 0
Serial Interface 0 can operate in 4 modes:
Mode 0:
Mode 1:
Mode 2:
Mode 3:
Variable Baud Rates for Serial Interface 0
Variable baud rates for modes 1 and 3 of serial interface 0 can be derived from either timer 1
or a dedicated Baudrate Generator.
The baud rate is generated by a free running 10-bit timer with programmable reload register.
Mode 1.3 baud rate =
The default value after reset in the reload registers S0RELL and S0RELH provide a baud rate
of 4.8 kBaud (SMOD = 0) or 9.6 kBaud (SMOD = 1) at 12 MHz oscillator frequency. This guar-
antees full compatibility to the SAB 80C517.
Semiconductor Group
Mode 1.3 baud rate =
Serial data enters and exits through R
Shift register mode:
clock 8 data bits are transmitted/received (LSB first). The baud rate is fixed at
1/12 of the oscillator frequency.
8-bit UART, variable baud rate:
10-bit are transmitted (through T
bit (0), 8 data bits (LSB first), and a stop bit (1). On reception, the stop bit
goes into RB80 in special function register S0CON. The baud rate is
variable.
9-bit UART, fixed baud rate:
11-bit are transmitted (through T
bit (0), 8 data bits (LSB first), a programmable 9th, and a stop bit (1).
On transmission, the 9th data bit (TB80 in S0CON) can be assigned to the
value of 0 or 1. For example, the parity bit (P in the PSW) could be moved
into TB80 or a second stop bit by setting TB80 to 1. On reception the 9th
data bit goes into RB80 in special function register S0CON, while the stop
bit is ignored. The baud rate is programmable to either 1/32 or 1/64 of the
oscillator frequency.
9-bit UART, variable baud rate:
11-bit are transmitted (through T
bit (0), 8 data bits (LSB first), a programmable 9th, and a stop bit (1). In
fact, mode 3 is the same as mode 2 in all respects except the baud rate.
The baud rate in mode 3 is variable.
64*(2
2
SMOD
10
*
-S0REL)
f
OSC
55
D0) or received (through R
D0) or received (through R
D0) or received (through R
D0. T
D0 outputs the shift
SAB 80C517A/83C517A-5
D0): a start
D0): a start
D0): a start
1994-05-01