NEC uPD78056Y - Manual (Page 354)

354
CHAPTER 17 SERIAL INTERFACE CHANNEL 0 (
µ
PD78054Y Subseries)
(4) Interrupt timing specify register (SINT)
This register sets the bus release interrupt and address mask functions and displays the SCK0/SCL pin level
status. SINT is set with a 1-bit or 8-bit memory manipulation instruction.
RESET input sets SINT to 00H.
Figure 17-6. Interrupt Timing Specify Register Format (1/2)
Notes 1. Bit 6 (CLD) is a read-only bit.
2. When not using the I 2 C mode, set CLC to 0.
Used in I 2 C bus mode.
Make SCL pin enter high-impedance state unless serial transfer is being performed.
(except for clock line which is kept high)
Used to enable master device to generate start condition and stop condition signals.
<6> <5> <4> <3> <2> 1 0 7
Symbol
SINT 0 CLD SIC SVAM CLC WREL WAT1 WAT0 FF63H 00H R/W Note 1
Address After Reset R/W
WREL
0 Wait state has been cancelled.
Cancels wait state. Automatically cleared to 0 when the state is cancelled.
(Used to cancel wait state by means of WAT0 and WAT1.)
CLC
0
1
Clock Level Control Note 2
Used in I 2 C bus mode.
Make output level of SCL pin low unless serial transfer is being performed.
R/W
1
Wait Sate Cancellation Control
R/W
WAT1
0
1
Wait and Interrupt Control
Generates interrupt service request at rising edge of 8th SCK0 clock cycle.
(keeping clock output in high impedance)
R/W WAT0
0
0 Used in I 2 C bus mode. (8-clock wait)
Generates interrupt service request at rising edge of 8th SCK0 clock cycle.
(In the case of master device, makes SCL output low to enter wait state after 8 clock pulses are
output. In the case of slave device, makes SCL output low to request wait state after 8 clock
pulses are input.)
1 1 Used in I 2 C bus mode. (9-clock wait)
Generates interrupt service request at rising edge of 9th SCK0 clock cycle.
(In the case of master device, makes SCL output low to enter wait state after 9 clock pulses are
output. In the case of slave device, makes SCL output low to request wait state after 9 clock
pulses are input.)
0 Setting prohibited 1