GMS90 Hynix Semiconductor, GMS90 Datasheet - Page 25

• Manufacturer Part Number: GMS90
• Description: 8-BIT SINGLE-CHIP MICROCONTROLLERS
• Manufacturer: Hynix Semiconductor

GMS90 Series
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
Table 7. Formulas for Calculating Baud rates
Dec. 1998 Ver 3.0
Mode
Timer 1 (16-bit timer)
0
1
2
3
8-bit auto reload)
(8-bit timer with
derived from
Baud Rate
Oscillator
Timer 2
SM0
0
0
1
1
SCON
SM1
0
1
0
1
Interface Mode
Timer 1/2 overflow rate
Timer 1/2 overflow rate
1,3
1,3
1,3
f
----------- -
0
2
OSC
32
Baudrate
f
----------- -
OSC
12
or
f
----------- -
OSC
64
Serial data enters and exits through RxD.
TxD outputs the shift clock. 8-bit are transmit-
ted/received (LSB first)
8-bit UART
10 bits are transmitted (through TxD) or
received (RxD)
9-bit UART
11 bits are transmitted (TxD) or received (RxD)
9-bit UART
Like mode 2 except the variable baud rate
--------------------------------------------------------------------------------- -
32
2
----------------- -
2
----------------- -
SMOD
SMOD
32
32
65536
2
----------------- -
SMOD
Baudrate
64
------------------------------------------------- -
12
Timer 1 overflow
–
f
----------- -
f
OSC
OSC
Description
12
RC2H RC2L
256
f
f
OSC
OSC
–
TH1
21