Spi status register – Rainbow Electronics AT75C220 User Manual
Page 132
AT75C220
132
SPI Status Register
Register Name: SP_SR
Access Type: Read-only
Reset Value: 0x0
•
RDRF: Receive Data Register Full
0 = No data has been received since the last read of SP_RDR.
1 = Data has been received and the received data has been transferred from the serializer to SP_RDR since the last
read of SP_RDR.
•
TDRE: Transmit Data Register Empty
0 = Data has been written to SP_TDR and not yet transferred to the serializer.
1 = The last data written in the Transmit Data Register has been transferred to the serializer.
TDRE equals zero when the SPI is disabled or at reset. The SPI enable command sets this bit to one.
•
MODF: Mode Fault Error
0 = No mode fault has been detected since the last read of SP_SR.
1 = A mode fault occurred since the last read of the SP_SR.
•
OVRES: Overrun Error Status
0 = No overrun has been detected since the last read of SP_SR.
1 = An overrun has occurred since the last read of SP_SR.
An overrun occurs when SP_RDR is loaded at least twice from the serializer since the last read of the SP_RDR.
•
SPENDTX: SPI End of Transmission
0 = No end of data transmission detected.
1 = End of data transmission detected.
•
SPENDRX: SPI End of Reception
0 = No end of data reception detected.
1 = End of data reception detected.
•
SPIENS: SPI Enable Status
0 = SPI is disabled.
1 = SPI is enabled.
31
30
29
28
27
26
25
24
–
–
–
–
–
–
–
–
23
22
21
20
19
18
17
16
–
–
–
–
–
–
–
SPIENS
15
14
13
12
11
10
9
8
–
–
–
–
–
–
–
–
7
6
5
4
3
2
1
0
–
–
SPENDRX
SPENDTX
OVRES
MODF
TDRE
RDRF