Rainbow Electronics AT75C220 - Manual (Page 125)

AT75C220
125
Slave Mode
In slave mode, the SPI waits for NPCSS to go active low
before receiving the serial clock from an external master. CPOL, NCPHA and BITS fields of SP_CSR0 are used to
define the transfer characteristics. The other chip select
registers are not used in slave mode.
Figure 30. SPI in Slave Mode
S
R
Q
T
D
R
E
R
D
R
F
O
V
R
E
S
P
I
E
N
S
Serializer
SCK
SPIDIS SPIEN
SP_IER
SP_IDR
SP_IMR
SP_SR
MISO
LSB MSB
NSS
MOSI
SPIRQ
SP_RDR
RD
SP_TDR
TD