Bt Mode Transfer Flow - Renesas H8S Family Hardware Manual

Section 19 LPC Interface (LPC)
19.4.4

BT Mode Transfer Flow

Figure 19.6 shows the write transfer flow and figure 19.7 shows the read transfer flow in BT
mode.
Slave
Slave waits for the H2B_ATN bit (interrupt from
host) is set.
Confirms the CLR_WR_PTR bit.
The CRWPI bit in BTSR1 is set to notify write
pointer clearing as an interrupt to slave.
Confirms host write is started.
The HBTWI bit in BTSR0 is set.
Confirms the H2B_ATN bit is set.
The H2BI bit in BTSR1 is set.
Slave sets the B_BUSY bit in BTCR.
Slave reads data from the BTDTR buffer.
Slave clears the H2B_ATN bit in BTCR.
Slave clears the B_BUSY bit in BTCR to indicate
transfer completion.
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Wait for
B_BUSY = 0
Wait for
H2B_ATN = 0
Clear write pointer
Generate slave
interrupt
Write BTDTR buffer
Generate slave
interrupt
H2B_ATN = 1
Generate slave
interrupt
B_BUSY = 1
Read BTDTR buffer
H2B_ATN = 0
B_BUSY = 0
Figure 19.6 BT Write Transfer Flow
Host
Host confirms the B_BUSY bit in BTCR.
Host confirms the H2B_ATN bit in BTCR.
Host clears write pointer by setting the CLR_WR_PTR
bit in BTCR.
Host writes data of 1 to n bytes to the BTDTR buffer.
Host sets the H2B_ATN bit in BTCR to indicate data write
completion to the buffer for the BT interface.