
CHAPTER 5 PERIPHERAL HARDWARE FUNCTION
182
(8) INTCSI control circuit
This circuit controls generation of an interrupt request. The interrupt request (INTCSI) is generated in the
following cases. When the interrupt request is generated, an interrupt request flag (IRQCSI) is set (refer to
Fig. 6-1 Block Diagram of Interrupt Control Circuit
).
In 3-line and 2-line serial I/O modes
The interrupt request is generated each time eight serial clocks have been counted.
In SBI mode
When WUP
Note
= “0” ... The interrupt request is generated each time eight serial clocks have been counted.
When WUP = “1” ... The interrupt request is generated when the value of SVA and that of SIO coincide
after an address has been received.
Note
WUP ... Wake-up function specification bit (bit 5 of CSIM)
(9) Serial clock control circuit
This circuit controls the supply of the serial clock to the shift register. It also controls the clock output to the
SCK pin when the internal system clock is used.
(10) Busy/acknowledge output circuit and bus release/command/acknowledge circuit
These circuits output and detect control signals in the SBI mode. They do not operate in the three-line and
two-line serial I/O modes.
(11) P01 output latch
This latch generates the serial clock via software after eight serial clock have been generated.
It is set to “1” when the reset signal is input.
To select the internal system clock as the serial clock, set the P01 output latch to “1”.