77
CHAPTER 5. PERIPHERAL HARDWARE FUNCTIONS
Remarks 1. The operating mode can be selected according to the setting of CSIE and CSIM3.
CSIE CSIM3 Operating Mode
0×Operation-halted mode
1 0 3-wire serial I/O mode
1 1 SBI mode
2. The P10/SCK pin status depends on the setting of CSIE and CSIM0 as shown below.
CSIE CSIM1 P10/SCK Pin Status
0 0 Input port
0 1 High-level output
1 0 Serial clock input (high impedance)
1 1 Serial clock output (high-level output)
3. The following procedure should be used to clear CSIE during a serial transfer.
Clear the interrupt enable flag to set the interrupt disabled state.
Clear CSIE.
Clear the interrupt request flag.
Example 1. This example selects fXX/24 as the serial clock, generates an IRQCSI serial interrupt at the end of each
serial transfer, and selects the mode in which serial transfers are performed in the SBI mode with
the SB0 pin as the serial data bus.
MOV XA, #10001010B
MOV CSIM, XA ; CSIM 10001010B
2. To enable serial transfers in accordance with the contents of CSIM.
SET1 CSIE