www.digiembedded.com
159
Memory Controller
Access: Read, big endian, 16-bit external
bus
External data mapping on to system
databus
Internal
transfer
width
HRDATA to DATA
HSIZE
[2:0]
HADDR
[1:0]
ADDROUT
[1:0]
BLSOU
T [1:0]
[31:24] 23:16] [15:8] [7:0]
Word (2
transfers
010 -- 1-
0-
00
00
-
[15:8]
-
[7:0]
[15:8]
-
[7:0]
-
Halfword 001 1- 1- 00 - - [15:8] [7:0]
Halfword 001 0- 0- 00 [15:8] [7:0] - -
Byte000111- 10---[7:0]
Byte 000 10 1- 01 - - [15:8] -
Byte 000 01 0- 10 - [7:0] - -
Byte 000 00 0- 01 [15:8] - - -
Table 86: Big endian read, 16-bit external bus
Access: Read, big endian, 32-bit external
bus
External data mapping on to system
databus
Internal
transfer
width
HRDATA to DATA
HSIZE
[2:0]
HADDR
[2:1]
ADDROUT
[1:0]
BLSOU
T [3:0]
[31:24] 23:16] [15:8] [7:0]
Word 010 -- -- 0000 [31:24] [23:16] [15:8] [7:0]
Halfword 001 1- -- 1100 - - [15:8] [7:0]
Halfword (2
transfers)
001 0- -- 0011 [31:24] [23:16] - -
Byte 000 11 -- 1110 ---[7:0]
Byte 000 10 -- 1101 - - [15:8] -
Table 87: Big endian read, 32-bit external bus