Essi data path programming model (shfd = 0) -31, Figure 7-12 and, Figure 7-12 – Motorola DSP56301 User Manual
Page 229
ESSI Programming Model
Enhanced Synchronous Serial Interface (ESSI)
7
-31
Figure 7-12. ESSI Data Path Programming Model (SHFD = 0)
SRD
ESSI Receive Data
Register
Serial
Receive
Shift
Register
24 Bit
WL1, WL0
24-bit Data
0
0
0
16-bit Data
12-bit Data
8-bit Data
LSB
LSB
LSB
LSB
MSB
Least Significant
Zero Fill
16 Bit
12 Bit
8 Bit
(a) Receive Registers
STD
ESSI Transmit Data
Register
ESSI Transmit
Shift Register
24-bit Data
0
0
0
16-bit Data
12-bit Data
8-bit Data
LSB
LSB
LSB
LSB
Least Significant
Zero Fill
(b) Transmit Registers
Transmit High Byte
Transmit Middle Byte
Transmit Low Byte
Transmit High Byte
Transmit Middle Byte
Transmit Low Byte
23
16 15
8 7
0
23
16 15
8
7
0
7
0 7
0
7
0
7
0 7
0 7
0
MSB
MSB
MSB
Note:
Data is transmitted MSB first if SHFD = 0.
4-bit fractional format (ALC = 0).
32-bit mode is not shown.
Receive High Byte
Receive Middle Byte
Receive Low Byte
Receive High Byte
Receive Middle Byte
Receive Low Byte
23
16 15
8 7
0
23
16 15
7
0
7
0 7
7
0
7
0 7
0 7
0
MSB
MSB
MSB
MSB
0
0
Note:
Data is received MSB first if SHFD = 0.
24-bit fractional format (ALC = 0).
32-bit mode is not shown.