MC9S12XD256CAG Datasheet, PDF (798/1348 Pages) Freescale Semiconductor, Inc – MC9S12XDP512 Data Sheet

Chapter 21 External Bus Interface (S12XEBIV2)
Table 21-17. Access in Normal Expanded Mode
Access
DATA[15:8]
DATA[7:0]
RE WE UDS LDS
I/O data(addr) I/O data(addr)
Word write of data on DATA[15:0] at an even and even+1 address 1 0 0 0 Out data(even) Out data(odd)
Byte write of data on DATA[7:0] at an odd address
1 0 1 0 In
x
Out data(odd)
Byte write of data on DATA[15:8] at an even address
1 0 0 1 Out data(even) In
x
Word read of data on DATA[15:0] at an even and even+1 address 0 1 0 0 In data(even) In data(odd)
Byte read of data on DATA[7:0] at an odd address
0 1 1 0 In
x
In data(odd)
Byte read of data on DATA[15:8] at an even address
Indicates No Access
Unimplemented
0 1 0 1 In data(even) In
x
1 1 1 1 In
x
In
x
1 1 1 0 In
x
In
x
1 1 0 1 In
x
In
x
21.4.5.2 Emulation Modes and Special Test Mode
In emulation modes and special test mode, the external signals LSTRB, R/W, and ADDR0 indicate the
access type (read/write), data size and alignment of an external bus access. Misaligned accesses to the
internal RAM and misaligned XGATE PRR accesses in emulation modes are the only type of access that
are able to produce LSTRB = ADDR0 = 1. This is summarized in Table 21-18.
Table 21-18. Access in Emulation Modes and Special Test Mode
Access
Word write of data on DATA[15:0] at an even and even+1
address
Byte write of data on DATA[7:0] at an odd address
Byte write of data on DATA[15:8] at an even address
Word write at an odd and odd+1 internal RAM address
(misaligned — only in emulation modes)
Word read of data on DATA[15:0] at an even and even+1
address
Byte read of data on DATA[7:0] at an odd address
Byte read of data on DATA[15:8] at an even address
Word read at an odd and odd+1 internal RAM address
(misaligned - only in emulation modes)
DATA[15:8]
DATA[7:0]
R/W LSTRB ADDR0
I/O data(addr) I/O data(addr)
0
0
0 Out data(even) Out data(odd)
0
0
0
1
0
1
1
In
x
Out data(odd)
0 Out data(odd) In
x
1 Out data(odd+1) Out data(odd)
1
0
0
In data(even) In data(even+1)
1
0
1
1
1
1
1
In
x
In data(odd)
0
In data(even) In
x
1
In data(odd+1) In data(odd)
MC9S12XDP512 Data Sheet, Rev. 2.21
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