IBM PowerPC 405GP User Manual

5:6 DRW SDRAM Width Must be set to 2'bOO.
0032-bit
01 Reserved
10 Reserved
11 Reserved
7:8
BRPF Burst Read Prefetch Granularity Most applications should set with field to
00 Reserved 2'b01.
01 16 bytes
1032 bytes
11 Reserved
9
ECCDD
ECC Driver
Disable
Regardless
of whether ECC checking is
o Check bit data output on ECC7:0. enabled, SDRAM writes cause the
1
ECC7:0 are placed in high-Z state.
PPC405GP to output check bit data on
ECC7:0. If ECC is not used, setting
ECCDD=1
disables these drivers.
10 EMDULR Enable Memory Data Unless Read
o MemDataO:31 are high-Z unless a
memory write is being performed.
1 MemDataO:31 are driven
unless a
memory read is being performed.
11 :31
}(""',
'.>":',
Reserved
15.3.2 Memory Controller Status (SDRAMO_STATUS)
The Memory Controller Status Register (SDRAMO_STATUS) allows software to determine the current
state of the SDRAM controller. If SDRAMO_STATUS[MRSCMP]=O the SDRAM is not accessible for
either read or write operations. Similarly, the SDRAM is also inaccessible when the SDRAM is in self-
refresh mode, SDRAMO_STATUS[SRSTATUS]=1.
MRSCMP
+
31
1
t
SRSTATUS
Figure 15-3. Memory Controller Status (SDRAMO_STATUS)
o
2:31
MRSCMP Mode Register Set Complete
o MRS not complete
1 MRS completed
SRSTATUS Self-Refresh State
o Not in Self-Refresh Mode
1 Self-Refresh Mode
Reserved
Set to 1 when the SDRAM controller completes
the Mode Register Set Command, which results
from setting SDRAMO_CFG[DCE].
Clearing SDRAMO_CFG[DCE]
causes this bit to
clear in the following MemClkOut1:0 cycle.
See "Self-Refresh"
on page 15-19.
SDRAM Controller
15-5

IBM PowerPC 405GP Specifications

General

Brand	IBM
Model	PowerPC 405GP
Category	Computer Hardware
Language	English