Serial Peripheral Interface Controller
UG0331 User Guide Revision 15.0
528
14.4.3
SPI Register Details
This section describes the SPI registers in detail.
14.4.3.1 SPI Control Register (CONTROL)
The following table provides details about the SPI Control register. Using this register, the SPI mode
(Master/Slave), the type of the protocol it uses, and the data frame count can be set.
CTRL1
0x44
R/W
0x01
Aliased
register bits 15:8. This register allows
byte operations from an 8-bit processor in the fabric. It is
not intended for access from internal MSS masters.
CTRL2
0x48
R/W
0x0
Aliased
register bits 23:16. This register
allows byte operations from an 8-bit processor in the
fabric. It is not intended for access from internal MSS
masters.
CTRL3
0x4C
R/W
0x0
Aliased
register bits 25:24. This register
allows byte operations from an 8-bit processor in the
fabric. It is not intended for access from internal MSS
masters.
Table 500 •
CONTROL
Bit
Number Name
R/W
Reset
Value
Description
31
RESET
R/W
1
0: SPI is enabled
1: SPI is held in Power reset state.
30
OENOFF
R/W
0
0: SPI output enable active as required
1: SPI output enable is not asserted. Allows multiple slaves to share a
single slave select signal with a single master.
29
BIGFIFO
R/W
0
Alters FIFO depth when frame size is [4-8] bits.
0: FIFO depth is 4 frames.
1: FIFO depth is 32 frames when frame size is [9-16] bits FIFO depth is
16; and when frame size is [17-32] bits FIFO depth is 8.
28
CLKMODE
R/W
0
Specifies the methodology used to calculate the SPICLK divider.
0: SPICLK = 1 / (2
C 1
) where CLK_GEN = 0 to 15.
1: SPICLK = 1 / (2 × (C 1)) where CLK_GEN = 0 to 255.
27
FRAMEURUN
R/W
0
0: The under-runs are generated whenever a read is attempted from an
empty transmit FIFO.
1: The under-run condition will be ignored for the complete frame, if the
first data frame read resulted in a potential overflow; that is, the slave
was not ready to transmit any data. If the first data frame is read from
the FIFO and transmitted, an under-run will be generated, when the
FIFO becomes empty for any of the remaining packet frames (that is,
while SSEL is active). Master operation does not create a transmit FIFO
under-run condition.
26
SPS
R/W
0
Defines slave select behavior. Refer to
25
SPH
R/W
0
Clock phase
24
SPO
R/W
0
Clock polarity
[23:8]
TXRXDFCOUNT R/W
0001
Number of data frames to be sent or received. Counts from 1.
Maximum value is 0XFFFF.
Table 499 •
SPI Register Summary
(continued)
Register Name
Address Offset R/W
Reset Value Description