M38513M4 Datasheet, PDF (9/61 Pages) Mitsubishi Electric Semiconductor – SINGLE-CHIP 8-BIT CMOS MICROCOMPUTER

(1) Port P0, P1
Direction
register
Data bus
Port latch
(3) Port P21
Port XC switch bit
Direction
register
Data bus
Port latch
Sub-clock generating circuit input
(5) Port P23
I²C-BUS interface enable bit
SDA/SCL pin selection bit
Direction
register
Data bus
Port latch
SCL output
SCL input
(7) Port P25
P-channel output disable bit
Serial I/O enable bit
Transmit enable bit
I²C bus interface enable bit
SDA/SCL pin selection bit
Direction
register
Data bus
Port latch
Serial I/O output
SCL output
SCL input
Fig. 7 Port block diagram (1)
MITSUBISHI MICROCOMPUTERS
3851 Group
SINGLE-CHIP 8-BIT CMOS MICROCOMPUTER
(2) Port P20
Port XC switch bit
Direction
register
Data bus
Port latch
(4) Port P22
I² C-BUS interface enable bit
SDA/SCL pin selection bit
Direction
register
Data bus
Port latch
Oscillator
Port P21
Port XC switch bit
SDA output
(6) Port P24
I²C-BUS interface enable bit
SDA/SCL pin selection bit
Serial I/O enable bit
Receive enable bit
Data bus
Direction
register
Port latch
SDA input
SDA output
(8) Port P26
Serial I/O enable bit
Serial I/O clock selection bit
Serial I/O mode selection bit
Serial I/O enable bit
Direction
register
Data bus
Port latch
SDA input
Serial I/O input
Serial clock output
External clock input
9