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CHAPTER 17 SERIAL INTERFACE CHANNEL 0 (
μ
PD780058Y Subseries)
(6) Interrupt signal generator
This circuit controls interrupt request signal generation. It generates interrupt request signals according to
the settings of interrupt timing specification register (SINT) bits 0 and 1 (WAT0, WAT1) and serial operation
mode register 0 (CSIM0) bit 5 (WUP), as shown in Table 17-3.
(7) Acknowledge output circuit and stop condition/start condition/acknowledge detector
These two circuits output and detect various control signals in the I
2
C mode.
These do not operate in the 3-wire serial I/O mode and 2-wire serial I/O mode.
Table 17-3. Serial Interface Channel 0 Interrupt Request Signal Generation
Serial Transfer Mode
BSYE
WUP
WAT1
WAT0
ACKE
Description
3-wire or 2-wire serial I/O mode
0
0
0
0
0
An interrupt request signal is generated each time 8
serial clocks are counted.
Other than above
Setting prohibited
I
2
C bus mode (transmit)
0
0
1
0
0
An interrupt request signal is generated each time 8
serial clocks are counted (8-clock wait).
Normally, during transmission the settings WAT21,
WAT0 = 1, 0, are not used. They are used only when
wanting to coordinate receive time and processing
systematically using software. ACK information is
generated by the receiving side, thus ACKE should be
set to 0 (disable).
1
1
0
An interrupt request signal is generated each time 9
serial clocks are counted (9-clock wait).
ACK information is generated by the receiving side,
thus ACKE should be set to 0 (disable).
Other than above
Setting prohibited
I
2
C bus mode (receive)
1
0
1
0
0
An interrupt request signal is generated each time 8
serial clocks are counted (8-clock wait).
ACK information is output by manipulating ACKT by
software after an interrupt request is generated.
1
1
0/1
An interrupt request signal is generated each time 9
serial clocks are counted (9-clock wait).
To automatically generate ACK information, preset
ACKE to 1 before transfer start. However, in the case
of the master, set ACKE to 0 (disable) before receiving
the last data.
1
1
1
1
1
After address is received, if the values of the serial
I/O shift register 0 (SI00) and the slave address
register (SVA) match, and if the stop condition is
detected, an interrupt request signal is generated.
To automatically generate ACK information, preset
ACKE to 1 (enable) before transfer start.
Other than above
Setting prohibited
Remark
BSYE: Bit 7 of serial bus interface control register (SBIC)
ACKE: Bit 5 of serial bus interface control register (SBIC)