Datasheet

Section 16 LPC Interface (LPC)
Rev. 3.00 Sep. 28, 2009 Page 471 of 710
REJ09B0384-0300
16.4.4 BT Mode Transfer Flow
Figure 16.6 shows the write transfer flow and figure 16.7 shows the read transfer flow in BT
mode.
Wait for
B_BUSY = 0
Wait for
H2B_ATN = 0
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.
Confirms host write is started.
The HBTWI bit in BTSR0 is set.
Host sets the H2B_ATN bit in BTCR to indicate data write
completion to the buffer for the BT interface.
Clear write pointer
B_BUSY = 1
Generate slave
interrupt
Generate slave
interrupt
Generate slave
interrupt
Slave waits for the H2B_ATN bit (interrupt from
host) is set.
Slave reads data from the BTDTR buffer.
Slave clears the H2B_ATN bit in BTCR.
Confirms the CLR_WR_PTR bit.
The CRWPI bit in BTSR1 is set to notify write
pointer clearing as an interrupt to slave.
Confirms the H2B_ATN bit is set.
The H2BI bit in BTSR1 is set.
Slave sets the B_BUSY bit in BTCR.
Write BTDTR buffer
Read BTDTR buffer
H2B_ATN = 1
H2B_ATN = 0
B_BUSY = 0
Slave clears the B_BUSY bit in BTCR to indicate
transfer completion.
HostSlave
Figure 16.6 BT Write Transfer Flow