at91rm3400 ATMEL Corporation, at91rm3400 Datasheet - Page 244

• Manufacturer Part Number: at91rm3400
• Description: Atmel Advanced At91 Arm Microcontroller
• Manufacturer: ATMEL Corporation

SPI Receive Data Register
Name:
Access Type:
• RD: Receive Data
Data received by the SPI Interface is stored in this register right-justified. Unused bits read zero.
• PCS: Peripheral Chip Select
In Master Mode only, these bits indicate the value on the NPCS pins at the end of a transfer. Otherwise, these bits read
zero.
SPI Transmit Data Register
Name:
Access Type:
• TD: Transmit Data
Data to be transmitted by the SPI Interface is stored in this register. Information to be transmitted must be written to the
transmit data register in a right-justified format.
PCS: Peripheral Chip Select
This field is only used if Variable Peripheral Select is active (PS = 1).
If PCSDEC = 0:
If PCSDEC = 1:
244
PCS = xxx0
PCS = xx01
PCS = x011
PCS = 0111
PCS = 1111
(x = don’t care)
NPCS[3:0] output signals = PCS
31
23
15
31
23
15
–
–
–
–
7
7
AT91RM3400
SPI_RDR
Read-only
SPI_TDR
Write-only
NPCS[3:0] = 1110
NPCS[3:0] = 1101
NPCS[3:0] = 1011
NPCS[3:0] = 0111
forbidden (no peripheral is selected)
30
22
14
30
22
14
–
–
6
–
–
6
29
21
13
29
21
13
–
–
5
–
–
5
28
20
12
28
20
12
–
–
–
–
4
4
RD
RD
TD
TD
27
19
11
27
19
11
–
–
3
3
26
18
10
26
18
10
–
2
–
2
PCS
PCS
25
17
25
17
–
9
1
–
9
1
1790A–ATARM–11/03
24
16
24
16
–
–
8
0
8
0