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CHAPTER 17 SERIAL INTERFACE IIC0 (
µ
PD780344Y, 780354Y SUBSERIES ONLY)
User’s Manual U15798EJ2V0UD
(6) Serial clock counter
This counter counts the serial clocks that are output or input during transmit/receive operations and is used to
verify that 8-bit data was transmitted or received.
(7) Interrupt request signal generator
This circuit controls the generation of interrupt request signals (INTIIC0).
An I
2
C interrupt request is generated following either of two triggers.
• Falling edge of the eighth or ninth serial clock (set by WTIM0 bit
Note
)
• Interrupt request generated when a stop condition is detected (set by SPIE0 bit
Note
)
Note
WTIM0 bit: Bit 3 of the IIC control register 0 (IICC0)
SPIE0 bit: Bit 4 of the IIC control register 0 (IICC0)
(8) Serial clock controller
In master mode, this circuit generates the clock output via the SCL0 pin from the sampling clock.
(9) Serial clock wait controller
This circuit controls the wait timing.
(10) ACK output circuit, stop condition detector, start condition detector, and ACK detector
These circuits are used to output and detect various control signals.
(11) Data hold time correction circuit
This circuit generates the hold time for data corresponding to the falling edge of the serial clock.
17.3 Registers to Control Serial Interface IIC0
Serial interface IIC0 is controlled by the following four registers.
• IIC control register 0 (IICC0)
• IIC status register 0 (IICS0)
• IIC transfer clock select register 0 (IICCL0)
• IIC function expansion register 0 (IICX0)
(1) IIC control register 0 (IICC0)
This register is used to enable/disable I
2
C operations, set wait timing, and set other I
2
C operations.
IICC0 is set by a 1-bit or 8-bit memory manipulation instruction.
RESET input sets IICC0 to 00H.
Caution
In I
2
C bus mode, set the port mode register (PMXX) as follows. Set the output latch of a port
set to output mode (PMXX) to 0.
• Set P31 (SDA0) to output mode (PM31 = 0)
• Set P30 (SCL0) to output mode (PM30 = 0)
Содержание mPD780344 Series
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