BAT32G1x9 user manual | Chapter 20 Serial interface IICA
804 / 1149
Rev.1.02
FIG 20-30(1) start condition ~ address ~ data" of FIG-.20-30 is as follows:
①
If the master sets the start condition trigger set (STTn=1), the bus data line (SDAAn) drops and the start
condition is generated (SDAAn is changed from "1" to "0" by SCLAn=1). )
。
Thereafter, if a start
condition is detected, the master enters the master communication state (MSTSn=1) and after the hold
time elapses the bus clock line drops (SCLAn=0,1), ending the communication preparation.
②
If the master writes aW (transmit) to IICA shift register n (IICAn), the slave address is sent.
③
On the slave, if the receiving address and the local station address (the value of the SVAn) are the same
note, an ACK is sent to the master through hardware. The master detects ACK on the rising edge of the
9th clock (ACKDn=1).
④
The master generates an interrupt on the falling edge of the 9th clock (INTIICAn: address send end
interrupt). Slaves with the same address enter a waiting state (SCLAn=0,1) and an interrupt (INTIICAn:
address matching interrupt)
note
.
⑤
The master writes and transmits data to the IICAn registers, relieving the master of waiting.
⑥
If the slave lifts the wait (WRELn=1), the master begins to transmit data to the slave.
Note: If the sent address and the slave address are different, the slave does not return an ACK
(NACK:
SDAAn=1
)
to the master
, and does not generate an
INTIICAn
interrupt
(address matching interrupt) or enter a waiting
state.
However, the master generates ANTIICAn
interrupts
(address send end interrupts) for
both
ACK
and
NAK.
Remarks: 1
~(15)
A series of operational steps for data communication via the I2C bus.
FIG 20-30of the "(1) start condition ~ address ~ data" illustrates steps (1) ~ (6).
FIG 20-30 of the "(2) address ~ data ~ data" illustrates steps (3) ~ (10).
FIG 20-30of the "(3) data ~ data ~ stop condition" illustrates step (7) ~ .
○
15
2.n=0,1