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CHAPTER 15 SERIAL INTERFACE CHANNEL 0 (
μ
PD78018F SUBSERIES)
(3) SO0 latch
This latch retains the levels of SI0/SB0/P25 and SO0/SB1/P26 pins. It can also be directly controlled by
software. In the SBI mode, this latch is set when the eighth serial clock has been input.
(4) Serial clock counter
This counter counts the serial clocks output or input during transmit/receive operation, and checks whether
8-bit data has been transmitted/received.
(5) Serial clock control circuit
This circuit controls supply of the serial clock to the serial I/O shift register 0 (SIO0). When the internal system
clock is used, it also controls the clock output to the SCK0/P27 pin.
(6) Interrupt request signal generation circuit
This circuit controls generation of an interrupt request signal. It generates an interrupt request signal in the
following cases:
In 3-wire serial I/O mode and 2-wire serial I/O mode
Generates the interrupt request signal each time eight serial clocks have been counted.
In SBI mode
When WUP
Note
is 0..... Generates the interrupt request signal each time eight serial clocks have been
counted.
When WUP
Note
is 1..... Generates the interrupt request signal when the values of the serial I/O shift
register 0 (SIO0) and slave address register (SVA) coincide after an address has
been received.
Note
WUP : wake-up function specification bit. Bit 5 of serial operation mode register 0 (CSIM0). Clear
bit 5 (SIC) of the interrupt timing specification register (SINT) to 0 when using the wake-up function
(WUP = 1).
(7) Busy/acknowledge output circuit and bus release/command/acknowledge detection circuit
These circuits output and detect various control signals in the SBI mode.
They do not operate in the 3-wire serial I/O mode and 2-wire serial I/O mode.