Renesas rl78 Answering Machine User Manual


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RL78/G1A CHAPTER 13 SERIAL INTERFACE IICA
Figure 13-4. Format of Slave Address Register 0 (SVA0)
Symbol
SVA0
Address: F0234H After reset: 00H R/W
76543210
0
Note
A0A1A2A3A4A5A6
Note Bit 0 is fixed to 0.
(3) SO latch
The SO latch is used to retain the SDAA0 pin’s output level.
(4) Wakeup controller
This circuit generates an interrupt request (INTIICA0) when the address received by this register matches the
address value set to the slave address register 0 (SVA0) or when an extension code is received.
(5) 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.
(6) Interrupt request signal generator
This circuit controls the generation of interrupt request signals (INTIICA0).
An I
2
C interrupt request is generated by the following two triggers.
• Falling edge of eighth or ninth clock of the serial clock (set by the WTIM0 bit)
• Interrupt request generated when a stop condition is detected (set by the SPIE0 bit)
Remark WTIM0 bit: Bit 3 of IICA control register 00 (IICCTL00)
SPIE0 bit: Bit 4 of IICA control register 00 (IICCTL00)
(7) Serial clock controller
In master mode, this circuit generates the clock output via the SCLA0 pin from a sampling clock.
(8) Serial clock wait controller
This circuit controls the wait timing.
(9) ACK generator, stop condition detector, start condition detector, and ACK detector
These circuits generate and detect each status.
(10) Data hold time correction circuit
This circuit generates the hold time for data corresponding to the falling edge of the serial clock.
(11) Start condition generator
This circuit generates a start condition when the STT0 bit is set to 1.
However, in the communication reservation disabled status (IICRSV bit = 1), when the bus is not released (IICBSY
bit = 1), start condition requests are ignored and the STCF bit is set to 1.
(12) Stop condition generator
This circuit generates a stop condition when the SPT0 bit is set to 1.
R01UH0305EJ0200 Rev.2.00 570
Jul 04, 2013