Texas Instruments TM4C1294NCPDT User Manual

Register 3: QSSI Data (SSIDR), offset 0x008
Important: This register is read-sensitive. See the register description for details.
The SSIDR register is 16-bits wide. When the SSIDR register is read, the entry in the receive FIFO
that is pointed to by the current FIFO read pointer is accessed. When a data value is removed by
the QSSI receive logic from the incoming data frame, it is placed into the entry in the receive FIFO
pointed to by the current FIFO write pointer.
When the SSIDR register is written to, the entry in the transmit FIFO that is pointed to by the write
pointer is written to. Data values are removed from the transmit FIFO one value at a time by the
transmit logic. Each data value is loaded into the transmit serial shifter, then serially shifted out onto
the SSInDAT0/SSInTX pin at the programmed bit rate.
When a data size of less than 16 bits is selected, the user must right-justify data written to the
transmit FIFO. The transmit logic ignores the unused bits. Received data less than 16 bits is
automatically right-justified in the receive buffer.
QSSI Data (SSIDR)
QSSI0 base: 0x4000.8000
QSSI1 base: 0x4000.9000
QSSI2 base: 0x4000.A000
QSSI3 base: 0x4000.B000
Offset 0x008
Type RW, reset 0x0000.0000
16171819202122232425262728293031
reserved
ROROROROROROROROROROROROROROROROType
0000000000000000Reset
0123456789101112131415
DATA
RWRWRWRWRWRWRWRWRWRWRWRWRWRWRWRWType
0000000000000000Reset
DescriptionResetTypeNameBit/Field
Software should not rely on the value of a reserved bit. To provide
compatibility with future products, the value of a reserved bit should be
preserved across a read-modify-write operation.
0x0000ROreserved31:16
QSSI Receive/Transmit Data
A read operation reads the receive FIFO. A write operation writes the
transmit FIFO.
Software must right-justify data when the QSSI is programmed for a
data size that is less than 16 bits. Unused bits at the top are ignored by
the transmit logic. The receive logic automatically right-justifies the data.
0x0000RWDATA15:0
1249June 18, 2014
Texas Instruments-Production Data
Tiva
™
TM4C1294NCPDT Microcontroller

Texas Instruments TM4C1294NCPDT Specifications

General

Brand	Texas Instruments
Model	TM4C1294NCPDT
Category	Microcontrollers
Language	English