Fujitsu FR81S Manuale Utente
CHAPTER 40: MULTI-FUNCTION SERIAL INTERFACE
4. Registers
FUJITSU SEMICONDUCTOR LIMITED
CHAPTER : MULTI-FUNCTION SERIAL INTERFACE
FUJITSU SEMICONDUCTOR CONFIDENTIAL
76
⋅
When this bit is set to "0": Normal synchronous communication.
⋅
When this bit is set to "1": SPI communication supported.
CS3SPI
Serial chip select pin 3
SPI support bit
0
Normal synchronous transfer
1
SPI supported
Notes:
⋅
This bit can be changed only when transmission and reception are disabled (SCR:TXE=RXE="0").
⋅
In the slave mode (SCR:MS="0"), setting this bit has no effect.
⋅
When data format of chip select is disabled (ESCR:CSFE="0"), setting this bit has no effect.
[bit4] CS3BDS: Transfer direction select bit for chip select 3
If data format of chip select is enabled (ESCR:CSFE="1"), this bit is used to select whether to transfer the
transfer serial data from the least significant bit (LSB first, BDS="0") or from the most significant bit (MSB
first, BDS="1") when the serial chip select pin 3 is active.
CS3BDS
Serial chip select pin 3
Transfer direction select bit
0
LSB first (transfer from the least significant bit)
1
MSB first (transfer from the most significant bit)
Notes:
⋅
This bit can be changed only when transmission and reception are disabled (SCR:TXE=RXE="0").
⋅
In the slave mode (SCR:MS="0"), setting this bit has no effect.
⋅
When data format of chip select is disabled (ESCR:CSFE="0"), setting this bit has no effect.
[bit3 to bit0] CS3 L3, L2, L1, L0: Data length select bits for chip select 3
If data format of chip select is enabled (ESCR:CSFE="1"), these bits are used to specify the data length of
transmission/reception data when the serial chip select pin 3 is active.
CS3L3 CS3L2 CS3L1 CS3L0
Serial chip select pin 3
Data length select bits
0
0
0
0
8-bit length
0
0
0
1
5-bit length
0
0
1
0
6-bit length
0
0
1
1
7-bit length
0
1
0
0
9-bit length
0
1
0
1
10-bit length
0
1
1
0
11-bit length
0
1
1
1
12-bit length
1
0
0
0
13-bit length
1
0
0
1
14-bit length
1
0
1
0
15-bit length
1
0
1
1
16-bit length
1
1
0
0
20-bit length
1
1
0
1
24-bit length
1
1
1
0
32-bit length
MB91520 Series
MN705-00010-1v0-E
1389