UG-1262
Rev. B | Page 255 of 312
FLOW CONTROL REGISTERS
Address: 0x40004028, Reset: 0x0000, Name: SPI0_FLOW_CTL
Address: 0x40024028, Reset: 0x0000, Name: SPI1_FLOW_CTL
This register is only used in master mode.
Table 316. Bit Descriptions for SPI0_FLOW_CTL, SPI1_FLOW_CTL
Bits Bit
Name Settings
Description
Reset Access
[15:12] Reserved
Reserved.
0x0 R
[11:8]
RDBURSTSZ
Read Data Burst Size Minus 1. This field specifies the number of bytes to be received minus 1 in
a
single burst from a slave before waiting for flow control. This bit is not valid if
SPIx_FLOW_CTL,
Bits[1:0] = 0b00. For all other values of SPIx_FLOW_CTL, Bits[1:0], this field is
valid. This field can take values from 0 to 15, implying a read burst of 1 byte to 16 bytes. This
mode is useful for reading fixed width conversion results periodically.
0x0 R/W
[7:5] Reserved
Reserved.
0x0 R
4
RDYPOL
Polarity of P0.3 Line. This field specifies the polarity of the P0.3 pin, which indicates that
the read data of the slave is ready. If SPIx_FLOW_CTL, Bits[1:0] = 0b10, this field refers to
the polarity of the P0.3 pin. Otherwise, if SPIx_FLOW_CTL, Bits[1:0] = 0b11, this field refers to
the polarity of the MISO line. For all other values of SPIx_FLOW_CTL, Bits[1:0], this bit is ignored.
0x0 R/W
0
Polarity is active high. SPI master waits until P0.3 becomes high.
1
Polarity is active low. SPI master waits until P0.3 becomes low.
[3:2] Reserved
Reserved.
0x0 R
[1:0]
MODE
Flow Control Mode. Flow control configuration for data reads. When the P0.3 signal is used for
flow control, P0.3 can be any control signal that is tied to this P0.3 input of the SPI module.
0x0 R/W
00
Flow control is disabled.
01
Flow control is based on timer SPIx_WAIT_TMR.
10
Flow control is based on P0.3 signal.
11
Flow control is based on MISO pin.
WAIT TIMER FOR FLOW CONTROL REGISTERS
Address: 0x4000402C, Reset: 0x0000, Name: SPI0_WAIT_TMR
Address: 0x4002402C, Reset: 0x0000, Name: SPI1_WAIT_TMR
This register is only used in master mode.
Table 317. Bit Descriptions for SPI0_WAIT_TMR, SPI1_WAIT_TMR
Bits Bit
Name
Settings
Description
Reset Access
[15:0]
VALUE
Wait Timer for Flow Control. This field specifies the number of SCLK cycles to wait before
continuing the SPI read. This field can take values of 0 to 65,535. This field is only valid if
SPIx_FLOW_CTL, Bits[1:0] = 0b01b. For all other values of SPIx_FLOW_CTL, Bits[1:0], this field
is ignored. A value of 0 implies a wait time of 1 SCLK cycle.
0x0000 R/W
CHIP SELECT OVERRIDE REGISTERS
Address: 0x40004034, Reset: 0x0000, Name: SPI0_CS_OVERRIDE
Address: 0x40024034, Reset: 0x0000, Name: SPI1_CS_OVERRIDE
This register is only used in master mode.
Table 318. Bit Descriptions for CS_OVERRIDE
Bits Bit
Name
Settings
Description
Reset Access
[15:2] Reserved
Reserved.
0x0 R
[1:0]
CTL
Chip Select Override Control. This bit overrides the chip select output from the master state
machine. This bit may be needed for special SPI transfers. Do not use for normal SPI transfers.
0x0 R/W
00
Chip select is not forced.
01
Chip select is forced to drive 1.
10
Chip select is forced to drive 0.
11
Chip select is not forced.