HD404339 Datasheet, PDF (52/80 Pages) Hitachi Semiconductor – 4-bit HMCS400-Series microcomputer with large-capacity memory

HD404339 Series
Serial Interface
The MCU has a one-channel serial interface built in with the following features.
• One of 13 different internal clocks or an external clock can be selected as the transmit clock. The
internal clocks include the six prescaler outputs divided by two and by four, and the system clock.
• During idle status, the serial output pin can be controlled to be high or low output
• Transmit clock errors can be detected
• An interrupt request can be generated after transfer has completed when an error occurs
SO
SCK
SI
Idle
controller
I/O
controller
Octal
counter (OC)
Clock
1/2
1/2
Serial interrupt
request flag
(IFS)
Serial data
register (SR)
Transfer
control
signal
System
clock
ø_PER
Selector
3
Serial mode
register
(SMR)
Prescaler S (PSS)
Port mode
register C
(PMRC)
Figure 38 Serial Interface Block Diagram
50