GMS90C320 Datasheet, PDF (21/46 Pages) Hynix Semiconductor – HYNIX SEMICONDUCTOR INC. 8-BIT SINGLE-CHIP MICROCONTROLLERS

GMS90C320
Serial Interface (USART)
The serial port is full duplex and can operate in four modes (one synchronous mode, three asynchronous modes) as illustrated
in Table 6. The possible baud rates can be calculated using the formulas given in Table 7.
Table 6
USART Operating Modes
Mode
0
1
2
3
SCON
SM0 SM1
0
0
0
1
1
0
1
1
Baudrate
Description
-^ƒ---^O----^S----^C---
12
Timer 1/2 overflow rate
-^ƒ---^O----^S----^C---
32
or
-^ƒ---^O----^S----^C---
64
Timer 1/2 overflow rate
Serial data enters and exits through RxD.
TxD outputs the shift clock.
8-bit are transmitted/received (LSB first)
8-bit UART
10 bits are transmitted (through TxD) or
received (RxD)
9-bit UART
11 bits are transmitted (through TxD) or
received (RxD)
9-bit UART
Like mode 2 except the variable baud rate
Table 7
Formulas for Calculating Baud rates
Baud Rate
derived from
Oscillator
Interface Mode
0
2
Timer 1 (16-bit timer)
1, 3
(8-bit timer with 8-bit autore-
load)
1, 3
Timer 2
1, 3
Baud rate
-^ƒ---^O----^S----^C---
12
2_----^S_----^M_-----^O_----^D_------^×_-----^ƒ_---O_----S_----C_---
64
-²---^S----^M-----^O----^D------^×----^t--ⁱ-^m-----^e----^r---¹-----^o----^v---^e---^r--^f--^l-^o---^w------^r--^a---^e-^t---
32
3^----2^-----2×^---S--1^--M-2^----O-×^---D--(^--2^--×-5^----6^{ƒ---O-–---S--}T^--C--H^-----1^----)
--------------------------------^ƒ---^O-----^S---^C-----------------------------------
32 × [65536 – (RC2H,RC2L)]
OCT. 2000 Ver 1.2
17