MC81F4332 Datasheet, PDF (146/198 Pages) Finechips – ABOV SEMICONDUCTOR 8-BIT SINGLE-CHIP MICROCONTROLLERS

MC81F4x16
23. SERIAL I/O INTERFACE
SCK
fxx/2
SI
CSEL
M
SIOPS
U
8-bit P.S.
1/2
X
Prescaler Value = 1/(SIOPS +1)
3-Bit Counter Clear
CLK
CCLR
SIOIR
SIO INT request
SIOIE
SIO INT enable
SIO INT
SEDGE
(Edge Select)
SIOP
(Shift Enable)
SIOM
(Mode Select)
CLK _{8-Bit SIO Shift Buffer}
(SIODATA)
SO
DAT
(LSB/MSB First
8
Mode Select)
Data Bus
Figure 23-1 SIO Block Diagram
Serial I/O interface modules, SIO can interface with various types of external device that require serial
data transfer. The components of SIO function block are:
- 8-bit control register (SIOCR)
- Clock selector logic
- 8-bit data register (SIODAT)
- 8-bit pre-scaler register (SIOPS)
- 3-bit clock counter
- Serial data I/O pins (SI, SO)
- Serial clock pin (SCK)
The SIO module can transmit or receive 8-bit serial data at a frequency determined by its
corresponding control register settings. To ensure flexible data transmission rates, you can select
internal or external clock source.
146
October 19, 2009 Ver.1.35