Electronics America 8-Bit Single-Chip Microcontrollers User's Manual

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CHAPTER 18 SERIAL INTERFACE CHANNEL 1
Figure 18-12. Basic Transmission Mode Flowchart
ADTP : Automatic data transmit/receive address pointer
ADTI : Automatic data transmit/receive interval specify register
SIO1 : Serial I/O shift register 1
TRF : Bit 3 of automatic data transmit/receive control register (ADTC)
Start
Write transmit data
in buffer RAM
Set ADTP to the value (pointer
value) obtained by subtracting 1
from the number of transmit
data bytes
Set the transmission/reception
operation interval time in ADTI
Write any data to SIO1
(Start trigger)
Write transmit data from
buffer RAM to SIO1
Transmission operation
Pointer value = 0
No
TRF = 0
No
End
Yes
Yes
Decrement pointer value
Software Execution
Hardware Execution
Software Execution