
Enhanced Synchronous Serial Interface (ESSI)
23
Receive High Byte
7
23
16 15
Receive Middle Byte
0 7
16 15
87
0 7
0 7
Receive Low Byte
0
0
0
ESSI Receive Data
Register (Read Only)
SR
7
Receive High Byte
Receive Middle Byte
0 7
07
Receive Low Byte
0
ESSI Receive
Shift Register
MSB
8-bit Data
LSB
0
0
0
Least Significant
MSB
MSB
12-bit Data
16-bit Data
LSB
LSB
Zero Fill
MSB
(a) Receive Registers
24-bit Data
LSB
NOTES:
Data is received MSB first if SHFD = 0.
24-bit fractional format (ALC = 0).
32-bit mode is not shown.
23 16 15 8 7 0
ESSI Transmit Data
Transmit High Byte Transmit Middle Byte Transmit Low Byte
Register
7 0 7
0 7 0
(Write Only)
23
7
Transmit High Byte
16 15
Transmit Middle Byte
0 7
0 7
07
Transmit Low Byte
0
0
ESSI Transmit Shift
Register
24 Bit
16 Bit
12 Bit
8 Bit
ST
MSB
8-bit Data
LSB
0
0
0
WL1, WL0
MSB
12-bit Data
LSB
Least Significant
Zero Fill
MSB
MSB
16-bit Data
24-bit Data
LSB
NOTES:
LSB
(b) Transmit Registers
Data is received MSB first if SHFD = 0.
4-bit fractional format (ALC = 0).
32-bit mode is not shown.
Figure 7-13. ESSI Data Path Programming Model (SHFD = 1)
DSP56311 User’s Manual, Rev. 2
7-30
Freescale Semiconductor