Endianism Conversion
2-74
2.11.2 Conversion Through the MPUI
Swapping buffers are implemented at the boundary between the DSP and the
MPUI (See Figure 2–25).
The word and byte swapping can be programmed so swapping is individually
controlled for MPU memory access and non-MPU memory (peripheral and
MPU register).
Figure 2–25. DSP Endian Conversion, MPUI Port Boundary
MPU
system bus
(little
endian)
MPUI
Port
interface
DSP
DSP TI
MPU bus
Control
DSP endian conversion, MPUI boundary
Controls
MPUI port
Byte 0
Byte 1
Byte 1
Byte 0
API write swapping buffers
API read swapping buffers
Bytes
steering
logic
(write)
Bytes
steering
logic
(read)
16
System DMA
controller
(little
endian)
System
DMA
bus
(Big endian)
(Little endian)
peripheral
bus
Note:
The steering logic puts the byte/word/double-word in appropriate formats.
The MPUI port has a 16-bit data bus, thus all 32-bit accesses are divided into
two 16-bit accesses. 16-bit word swapping and byte swapping are program-
mable.
By default:
-
Byte swapping is disabled for all accesses.
-
16-bit word swapping is enabled for all accesses.