Cypress CY7C67200 Computer Drive User Manual


 
CY7C67200
Document #: 38-08014 Rev. *G Page 54 of 78
3Wire Enable (Bit 15)
The 3Wire Enable bit indicates if the MISO and MOSI data
lines are tied together allowing only half duplex operation.
1: MISO and MOSI data lines are tied together
0: Normal MISO and MOSI Full Duplex operation (not tied
together)
Phase Select (Bit 14)
The Phase Select bit selects advanced or delayed SCK phase.
This field only applies to master mode.
1: Advanced SCK phase
0: Delayed SCK phase
SCK Polarity Select (Bit 13)
This SCK Polarity Select bit selects the polarity of SCK.
1: Positive SCK polarity
0: Negative SCK polarity
Scale Select (Bits [12:9])
The Scale Select field provides control over the SCK
frequency, based on 48 MHz. See Table 34 for a definition of
this field. This field only applies to master mode.
Master Active Enable (Bit 7)
The Master Active Enable bit is a read-only bit that indicates if
the master state machine is active or idle. This field only
applies to master mode.
1: Master state machine is active
0: Master state machine is idle
Master Enable (Bit 6)
The Master Enable bit sets the SPI interface to master or
slave. This bit is only writable when the Master Active Enable
bit reads ‘0’, otherwise value will not change.
1: Master SPI interface
0: Slave SPI interface
SS Enable (Bit 5)
The SS Enable bit enables or disables the master SS output.
1: Enable master SS output
0: Disable master SS output (three-state master SS output, for
single SS line in slave mode)
SS Delay Select (Bits [4:0])
When the SS Delay Select field is set to ‘00000’ this indicates
manual mode. In manual mode SS is controlled by the SS
Manual bit of the SPI Control register. When the SS Delay
Select field is set between ‘00001’ to ‘11111’, this value
indicates the count in half bit times of auto transfer delay for:
SS LOW to SCK active, SCK inactive to SS HIGH, SS HIGH
time. This field only applies to master mode.
Table 34.Scale Select Field Definition for SCK Frequency
Scale Select [12:9] SCK Frequency
0000 12 MHz
0001 8 MHz
0010 6 MHz
0011 4 MHz
0100 3 MHz
0101 2 MHz
0110 1.5 MHz
0111 1 MHz
1000 750 KHz
1001 500 KHz
1010 375 KHz
1011 250 KHz
1100 375 KHz
1101 250 KHz
1110 375 KHz
1111 250 KHz
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