GMS81C5108 Datasheet, PDF (65/102 Pages) Hynix Semiconductor – HYNIX SEMICONDUCTOR INC. 8-BIT SINGLE-CHIP MICROCONTROLLERS

GMS81C5108
16. Serial Communication Interface
The SCI module allows 8-bits of data to be synchronously
transmitted and received. This is useful for communication
with other peripheral of microcontroller devices.This con-
sists of serial I/O data register, serial I/O mode register,
clock selection circuit octal counter and control circuit as
shown in Figure 16-1.
SIOM (Seriol I/O Mode Register)
R/W
R/W
R/W
Bit :
7
6
5
POL
MSBS
SIO1
R/W
4
SIO0
R/W
3
SICK1
R/W
2
SICK0
R/W
1
SIOST
R/W
0
SIOSF
ADDRESS : 0FE_H
RESET VALUE : 00000001_B
POL (Polarity Selection)
0 : Data Transmission at falling edge
(Received data latch at rising edge)
1 : Data Transmission at rising edge
(Received data latch at falling edge)
SIO[1:0] (Serial I/O Operation Mode)
00 : Normal Port (R05, R06, R07)
01 : Transmit Mode (SCK, SO, R07)
10 : Receive Mode (SCK, R06, SI)
11 : Transmit & Receive Mode (SCK, SO, SI)
SIOST (Serial I/O Operation Start Control)
0 : SIO Operation Stop
1 : SIO Operation Start
(After one SCK clock become “0”)
MSBS (MSB First Transmit and Receive Selection)
0 : LSB First
1 : MSB First
SICK[1:0] (Serial I/O Clock Source Selection)
00: f_MAIN ÷4 or f_SUB ÷4
01: f_MAIN ÷16 or f_SUB ÷16
10: T0O (Timer 0 Output)
11: External Clock
SIOSF (Serial I/O Status Flag)
0 : During SIO Operation
1 : SIO Operation Finished
SIOD (Serial I/O Data Register)
R/W
R/W
R/W
Bit :
7
6
5
SIOD7 SIOD6 SIOD5
R/W
4
SIOD4
R/W
3
SIOD3
R/W
2
SIOD2
R/W
1
SIOD1
R/W
0
SIOD0
ADDRESS : 0FF_H
RESET VALUE : Undefined
SCMR[1:0]
2
XIN
0X
SX_IN
1X
Pre-
scaler
SICK[1:0]
2
÷ ÷ fMAIN 2² or fSUB 2²
00
÷ ÷ fMAIN 2⁴ or fSUB 2⁴ ₀₁
POL
T0OV(Timer 0 Overflow) 10
R05
SCK
11
SIO[1:0] = 00
1
R07/SI
SICK[1:0] ≠ 11
& SIO[1:0] ≠ 00
SIO[1] = 1
0
1
MSBS
SIOST
Start
Complete
SIO Control Circuit
Clock
Shift Clock
SIOSF
Clear
Octal Counter
(3-Bit)
SCK
SIOIF
SIO
Interrupt
MSB
LSB
SIOD(8-Bit)
SIO Data Register
MSBS
0
R06/SO
1
SIO[0] = 1
Figure 16-1 SCI Registers and Block Diagram
62
JUNE 2001 Ver 1.0