ADuCM320 Hardware Reference Manual
UG-498
Rev. C | Page 135 of 196
SPI Configuration Register
Address: 0x40030010, Reset: 0x0000, Name: SPI1CON
Table 191. Bit Descriptions for SPI1CON
Bits
Bit Name
Description
Reset
Access
[15:14]
MOD
SPI IRQ mode bits. These bits configure when the Tx/Rx interrupts occur in
a transfer. For DMA Rx transfer, these bits should be 00.
0x0
RW
00: Tx interrupt occurs when 1 byte has been transferred. Rx interrupt
occurs when 1 or more bytes have been received into the FIFO.
01: Tx interrupt occurs when 2 bytes has been transferred. Rx interrupt
occurs when 2 or more bytes have been received into the FIFO.
10: Tx interrupt occurs when 3 bytes has been transferred. Rx interrupt
occurs when 3 or more bytes have been received into the FIFO.
11: Tx interrupt occurs when 4 bytes has been transferred. Rx interrupt
occurs when the Rx FIFO is full, or 4 bytes present.
13
TFLUSH
SPI Tx FIFO flush enable.
0x0
RW
0: clear this bit to disable Tx FIFO flushing.
1: set this bit to flush the Tx FIFO. This bit does not clear itself and should
be toggled if a single flush is required. If this bit is left high, then either the
last transmitted value or “0x00” is transmitted depending on the ZEN bit.
Any writes to the Tx FIFO are ignored while this bit is set.
12
RFLUSH
SPI Rx FIFO flush enable.
0x0
RW
0: clear this bit to disable Rx FIFO flushing.
1: set this bit to flush the Rx FIFO. This bit does not clear itself and should
be toggled if a single flush is required. If this bit is set all incoming data is
ignored and no interrupts are generated. If set and TIM = 0, a read of the
Rx FIFO initiates a transfer.
11
CON
Continuous transfer enable.
0x0
RW
0: DIS. Cleared by user to disable continuous transfer. Each transfer
consists of a single 8-bit serial transfer. If valid data exists in the SPI1TX
register, a new transfer is initiated after a stall period of 1 serial clock cycle.
1: EN. Set by user to enable continuous transfer. In master mode, the
transfer continues until no valid data is available in the Tx register. CS is
asserted and remains asserted for the duration of each 8-bit serial transfer
until Tx is empty.
10
LOOPBACK
Loopback enable.
0x0
RW
0: cleared by user to be in normal mode.
1: set by user to connect MISO to MOSI and test software.
9
OEN
Slave MISO output enable.
0x0
RW
0: clear this bit to disable the output driver on the MISO pin. The MISO pin
is open-circuit when this bit is clear.
1: set this bit for MISO to operate as normal.
8
RXOF
SPIRX overflow overwrite enable.
0x0
RW
0: cleared by user, the new serial byte received is discarded.
1: set by user, the valid data in the Rx register is overwritten by the new
serial byte received.
7
ZEN
Transmit zeros enable.
0x0
RW
0: clear this bit to transmit the last transmitted value when there is no valid
data in the Tx FIFO.
1: set this bit to transmit 0x00 when there is no valid data in the Tx FIFO.
6
TIM
SPI transfer and interrupt mode.
0x0
RW
0: cleared by user to initiate transfer with a read of the SPIRX register.
Interrupt only occurs when Rx is full.
1: set by user to initiate transfer with a write to the SPITX register. Interrupt
only occurs when Tx is empty.