Filter
Top Products
448
CHAPTER 19 SERIAL INTERFACE CHANNEL 1
(d) Automatic transmission/reception suspending and restart
Automatic transmission/reception can be temporarily suspended by setting bit 7 (CSIE1) of the serial
operating mode register 1 (CSIM1) to 0.
If during 8-bit data transfer, the transmission/reception is not suspended if bit 7 (CSIE1) is set to 0, it
is suspended upon completion of 8-bit data transfer.
When suspended, bit 3 (TRF) of the automatic data transmit/receive control register (ADTC) is set to
0 after transfer of the 8th bit, and all the port pins used with the serial interface pins for dual function
(P20/SI1, P21/SO1, P22/SCK1, P23/STB, and P24/BUSY) are set to the port mode.
For restart of automatic transmission/reception, remaining data can be transferred by setting CSIE1 to
1 and writing any data to the serial I/O shift register 1 (SIO1).
Cautions 1. If the HALT instruction is executed during automatic transmission/reception,
transfer is suspended and the HALT mode is set if during 8-bit data transfer. When
the HALT mode is cleared, automatic transmission/reception is restarted from the
suspended point.
2. When suspending automatic transmission/reception, do not change the operating
mode to 3-wire serial I/O mode while TRF = 1.
Figure 19-17. Automatic Transmission/Reception Suspension and Restart
CSIE1: Bit 7 of serial operating mode register 1 (CSIM1)
SCK1
SO1 D7 D6 D5 D4 D3 D2 D1 D0 D7 D6 D5 D4 D3 D2 D1 D0
SI1 D7 D6 D5 D4 D3 D2 D1 D0 D7 D6 D5 D4 D3 D2 D1 D0
Restart Command
CSIE1 = 1, Write to SIO1
Suspend
CSIE1 = 0 (Suspended Command)