Cirrus Logic EP93xx User Manual

Page 729

DS785UM1

23-17

Synchronous Serial Port

EP93xx User’s Guide

DATA:

Transmit / Receive FIFO:
Read - Receive FIFO
Write - Transmit FIFO

Note: The user should right-justify data when the SSP is programmed for a data size that is less

than 16 bits. Unused bits at the top are ignored by transmit logic. The receive logic
automatically right justifies.

SSPSR

Address:

0x808A_000C - Read Only

Default:

0x0000_0000

Definition:

SSPSR is a read-only status register, which contains bits that indicate the
FIFO fill status and the SSP busy status.

Bit Descriptions:

RSVD:

Reserved. Unknown During Read.

BSY:

SSP busy flag (read-only):
0 - SSP is idle.
1 - SSP is currently transmitting and / or receiving a frame
or the transmit FIFO is non-empty.

RFF:

Receive FIFO full (read-only):
0 - Receive FIFO is not full
1 - Receive FIFO is full

RNE:

Receive FIFO not empty (read-only):
0 - Receive FIFO is empty.
1 - Receive FIFO is not empty

TNF:

Transmit FIFO not full (read-only):
0 - Transmit FIFO is full.
1 - Transmit FIFO is not full.

TFE:

Transmit FIFO empty (read-only):
0 - Transmit FIFO is not empty
1 - Transmit FIFO is empty

RSVD

BSY

RFF

RNE

TNF

TFE