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CHAPTER 14
SERIAL INTERFACE SIO1
User’s Manual U12790EJ2V0UD
In 6-byte transmission (bit 6 (ARLD) and bit 7 (RE) of the automatic data transmit/receive control register (ADTC)
are 1 and 0, respectively) in repeat transmit mode, the buffer RAM operates as follows.
(i)
Before transmission (refer to Figure 14-16 (a))
After any data has been written to SIO1 (start trigger: this data is not transferred), transmit data 1
(T1) is transferred from the buffer RAM to SIO1. When transmission of the first byte is completed,
ADTP is decremented. Then transmit data 2 (T2) is transferred from the buffer RAM to SIO1.
(ii) Upon completion of transmission of 6 bytes (refer to Figure 14-16 (b))
When transmission of the sixth byte is completed, the interrupt request flag (CSIIF1) is not set. The
previous pointer value is assigned to ADTP.
(iii) 7th byte transmission point (refer to Figure 14-16 (c))
Transmit data 1 (T1) is transferred from the buffer RAM to SIO1 again. When transmission of the
first byte is completed, ADTP is decremented. Then transmit data 2 (T2) is transferred from the buffer
RAM to SIO1.
Figure 14-16. Buffer RAM Operation in 6-Byte Transmission (in Repeat Transmit Mode) (1/2)
(a) Before transmission
Transmit data 1 (T1)
Transmit data 2 (T2)
Transmit data 3 (T3)
Transmit data 4 (T4)
Transmit data 5 (T5)
Transmit data 6 (T6)
FADFH
FAC5H
FAC0H
SIO1
0
CSIIF1
5
ADTP
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