User Manual

AT75C220

131

SPI Transmit Data Register

Access Type:Write-only

Reset Value:–

• TD: Transmit Data

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.

• PCS: Peripheral Chip Select

This field is only used if variable peripheral select is active (PS = 1).

If PCSDEC = 0:

PCS = xxx0 NPCS[3:0] = 1110

PCS = xx01 NPCS[3:0] = 1101

PCS = x011 NPCS[3:0] = 1011

PCS = 0111 NPCS[3:0] = 0111

PCS = 1111 forbidden (no peripheral is selected)

(x = don’t care)

If PCSDEC = 1:

NPCS[3:0] output signals = PCS

31 30 29 28 27 26 25 24

––––––––

23 22 21 20 19 18 17 16

–––– PCS

15 14 13 12 11 10 9 8

76543210