LM3S5D91 Datasheet, PDF (515/1340 Pages) Texas Instruments – Stellaris® LM3S5D91 Microcontroller

Stellaris^® LM3S5D91 Microcontroller
Register 11: EPI Read Size 0 (EPIRSIZE0), offset 0x020
Register 12: EPI Read Size 1 (EPIRSIZE1), offset 0x030
This register selects the size of transactions when performing non-blocking reads with the
EPIRPSTDn registers. This size affects how the external address is incremented.
The SIZE field must match the external data width as configured in the EPIHBnCFG or EPIGPCFG
register if the WORD bit is clear in the EPIHBnCFG2 or EPIGPCFG2 register. If the WORD bit is set,
the SIZE field must be greater than or equal to the external data width.
SDRAM mode uses a 16-bit data interface. If SIZE is 0x1, data is returned on the least significant
bits (D[7:0]), and the remaining bits D[31:8] are all zeros, therefore the data on bits D[15:8] is lost.
If SIZE is 0x2, data is returned on the least significant bits (D[15:0]), and the remaining bits D[31:16]
are all zeros.
Note that changing this register while a read is active has an unpredictable effect.
EPI Read Size 0 (EPIRSIZE0)
Base 0x400D.0000
Offset 0x020
Type R/W, reset 0x0000.0003
31
30
29
28
27
26
25
24
23
22
21
20
19
18
17
16
reserved
Type RO
RO
RO
RO
RO
RO
RO
RO
RO
RO
RO
RO
RO
RO
RO
RO
Reset
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
15
14
13
12
11
10
9
8
7
6
5
4
3
2
1
0
reserved
SIZE
Type RO
RO
RO
RO
RO
RO
RO
RO
RO
RO
RO
RO
RO
RO
R/W
R/W
Reset
0
0
0
0
0
0
0
0
0
0
0
0
0
0
1
1
Bit/Field
31:2
1:0
Name
reserved
SIZE
Type
Reset Description
RO 0x0000.000 Software should not rely on the value of a reserved bit. To provide
compatibility with future products, the value of a reserved bit should be
preserved across a read-modify-write operation.
R/W
0x3
Current Size
Value Description
0x0 reserved
0x1 Byte (8 bits)
0x2 Half-word (16 bits)
0x3 Word (32 bits)
January 22, 2012
515
Texas Instruments-Production Data