Panasonic MN101L Series

Chapter 13
Serial Interface
Full-duplex UART Communication XIII - 51
 Data Storage to TXBUFn
In MSB first mode, write transmission data to TXBUFn in order from the upper bit.
For example, when transmitting 7-bit data, write data to TXBUFn from bp7 to bp1 as shown in Figure:13.4.2.
Each bit from A to G is transmitted in the order from G to A.
In LSB first mode, write transmission data to TXBUFn in order from the lower bit.
For example, when transmitting 7-bit data, write data to TXBUFn as shown in Figure:13.4.3.
Each bit from A to G is transmitted in the order from A to G.
Figure:13.4.2 Transmission Data Storage (MSB first)
Figure:13.4.3 Transmission Data Storage (LSB first)
 Data Storage to RXBUFn
In MSB first mode, reception data are stored in RXBUFn in order from the upper bit.
For example, when receiving 7-bit data, each bit from A to G (A is the first reception bit.) is stored in RXBUFn
from bp7 to bp1 as shown in Figure:13.4.4.
In LSB first mode, reception data are stored in RXBUFn in order from the lower bit.
For example, when receiving 7-bit data, each bit from A to G (A is the first reception bit.) is stored in RXBUFn
from bp0 to bp6 as shown in Figure:13.4.5.
Figure:13.4.4 Reception Data Storage (MSB first)
Figure:13.4.5 Reception Data Storage (LSB first)
01243
CDGBE
567
F
TXBUFn
A
01243
CD
AB
E
567
F
TXBUFn
G
0
RXBUFn
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CDAB EF G
01243
CD
B
E
567
G
F
A
RXBUFn