
Chapter 11
Serial Interface 0
XI - 14
Operation
nReceive bit Count and First Transfer bit
When the transfer bit count is 1 bit to 7 bits, the data storing method to the received data buffer RXBUF0
is different depending on the first transfer bit. At MSB first, data are stored to the lower bits of RXBUF0.
When there are 6 bits to be transfered, as shown on figure 11-3-3, if data "A" to "F" are stored to bp0 to
bp5 of RXBUF0, the transmission is operated from "F" to "A". At LSB first, data are stored to the upper
bits of RXBUF0. When there are 6 bits to be transfered, as shown on figure 11-3-4, if data "A" to "F" are
stored to bp2 to bp7 of RXBUF0, the transmission is operated from "A" to "F".
nTranfer bit Count and First Transfer bit
When the transfer bit is 1 bit to 7 bits, the data storing method to the transmission data buffer TXBUF0
is different, depending on the first transfer bit selection. At MSB first, use the upper bits of TXBUF0 for
storing. When there are 6 bits to be transfered, as shown on figure 11-3-1, if data "A" to "F" are stored to
bp2 to bp7 of TXBUF0, the transmission is operated from "F" to "A". At LSB first, use the lower bits of
TXBUF0 for storing. When there are 6 bits to be transfered, as shown on figure 11-3-2, if data "A" to "F"
are stored to bp0 to bp5 of TXBUF0, the transmission is operated from "A" to "F".
Figure 11-3-2
Transfer bit Count and First Transfer bit (starting with LSB)
Figure 11-3-1
Transfer bit Count and First Transfer bit (starting with MSB)
0
1
2
43
TXBUF0
C
D
A
B
E
5
6
7
F
0
1
2
43
TXBUF0
C
D
A
B
E
5
6
7
F
Figure 11-3-3
Receive bit Count and Transfer First bit (starting with MSB bit)
Figure 11-3-4
Receive bit Count and Transfer First bit (starting with LSB bit)
0
1
2
43
RXBUF0
C
D
A
B
E
5
6
7
F
0
1
2
43
RXBUF0
C
D
A
B
E
5
6
7
F