HD64F2168 Datasheet, PDF (610/874 Pages) Renesas Technology Corp – Renesas 16-Bit Single-Chip Microcomputer

Slave
Bit that indicates slave is ready for write transfer.
Issues when slave is ready for the next write transfer.
Host
Wait for BUSY = 0
Host confirms the BUSY bit in SMICFLG.
The bit indicates slave (this LSI) is ready for receiving a new control code.
When BUSY = 1, access from host is disabled.
Wait for
Host confirms the TX_DATA_RDY bit in SMICFLG.
TX_DATA_RDY = 1 The confirmation is unnecessary when Write Start control is issued.
A
Write control code Host writes the Write control code in SMICCSR.
Slave confirms that control code is written to SMICCSR
by host.
The CTLWI bit in SMICIR0 is set.
Slave waits for the BUSY bit in SMICFLG is set.
Slave confirms that valid data is written to SMICDTR
by host.
The HDTWI bit in SMICIR0 is set.
Slave confirms the rising edge of the BUSY bit in SMICFLG.
The BUSYI bit in SMICIR0 is set.
Generate slave
interrupt
Write transfer data Host writes transfer data in SMICDTR.
Generate slave
interrupt
BUSY = 1
Host sets the BUSY bit in SMICFLG.
Generate slave
interrupt
Slave clears the TX_DATA_RDY bit in SMICFLG.
TX_DATA_RDY = 0
Slave reads the control code in SMICCSR.
Read control code
Slave reads transfer data in SMICDTR according to
Write control code.
Read transfer data
Slave writes the status code to SMICCSR to notify
the processing completion status.
Write status code
Slave clears the BUSY bit in SMICFLG to indicate
transfer completion.
BUSY = 0
Generate host
interrupt
Abnormal
A
Read status code
Slave confirms that status code is read from SMICCSR
by host.
The STARI bit in SMICIR0 is set.
Normal
Generate slave
interrupt
Host confirms the falling edge of the BUSY bit in SMICFLG.
An interrupt is generated.
Host confirms the status code in SMICCSR.
In the case of normal completion, the status code is reflected to the next step.
In the case of abnormal completion, the status code is READY and an error
is kept.
Figure 16.4 SMIC Write Transfer Flow
Rev. 3.00, 03/04, page 570 of 830