at75c220 ATMEL Corporation, at75c220 Datasheet - Page 131

• Manufacturer Part Number: at75c220
• Description: Smart Internet Appliance Processor Siap
• Manufacturer: ATMEL Corporation

SPI Transmit Data Register
Register Name:SP_TDR
Access Type:Write-only
Reset Value:–
•
•
TD: Transmit Data
PCS: Peripheral Chip Select
Data that is 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.
This field is only used if variable peripheral select is active (PS = 1).
If PCSDEC = 0:
If PCSDEC = 1:
31
23
15
–
–
7
PCS = xxx0
PCS = xx01
PCS = x011
PCS = 0111
PCS = 1111
(x = don’t care)
NPCS[3:0] output signals = PCS
30
22
14
–
–
6
NPCS[3:0] = 1110
NPCS[3:0] = 1101
NPCS[3:0] = 1011
NPCS[3:0] = 0111
forbidden (no peripheral is selected)
29
21
13
–
–
5
28
20
12
–
–
4
TD
TD
27
19
11
–
3
26
18
10
–
2
PCS
25
17
–
9
1
24
16
–
8
0
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