NEC PD78F9488 - Manual (Page 235)

CHAPTER 12 SERIAL INTERFACE 1A0
User’s Manual U15331EJ4V1UD
235
(2) Automatic transmit/receive data setting
(a) Transmit data setting
<1> Write transmit data from the least significant address FFA0H of buffer RAM (up to FFAFH). The
transmit data should be in the order from higher address to lower address.
<2> Set the value obtained by subtracting 1 from the number of transmit data bytes to automatic data
transmit/receive address pointer 0 (ADTP0).
(b) Automatic transmit/receive mode setting
<1> Set bit 7 (CSIE10) and bit 5 (ATE0) of serial operation mode register 1A0 (CSIM1A0) to 1.
<2> Set bit 7 (RE0) of automatic data transmit/receive control register 0 (ADTC0) to 1.
<3> Set the data transmit/receive interval in automatic data transmit/receive interval specification
register 0 (ADTI0).
<4> Write any value to serial I/O shift register 1A0 (SIO1A0) (transfer start trigger).
Caution Writing any value to SIO1A0 orders the start of automatic transmission/reception
operation; the written value has no meaning.
The following operations are automatically carried out when (a) and (b) are carried out.
• After the buffer RAM data specified by ADTP0 is transferred to SIO1A0, transmission is carried out
(start of automatic transmission/reception).
• The received data is written to the buffer RAM address specified by ADTP0.
• ADTP0 is decremented and the next data transmission/reception is carried out. Data
transmission/reception continues until the ADTP0 decremental output becomes 00H and address
FFA0H data is output (end of automatic transmission/reception).
• When automatic transmission/reception is terminated, bit 3 (TRF0) of ADTC0 is cleared to 0.