Revision 1.1
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Integrated Functions (
Continued
)
G
13
12
RSVD
DIMM0_
COMP_BNK
Reserved:
Set to 0.
DIMM0 Component Banks (Banks 0 and 1):
Selects the number of component banks per module
bank for DIMM0:
0 = 2 Component banks
1 = 4 Component banks
Banks 0 and 1 must have the same number of component banks.
Reserved:
Set to 0.
DIMM0 Size (Banks 0 and 1):
Selects the size of DIMM1:
000 = 4 MB
010 = 16 MB
100 = 64 MB
001 = 8 MB
011 = 32 MB
101 = 128 MB
This size is the total of both banks 0 and 1. Also, banks 0 and 1 must be the same size.
Reserved:
Set to 0.
DIMM0 Page Size (Banks 0 and 1):
Selects the page size of DIMM0:
000 = 1 KB
010 = 4 KB
1xx = 16 KB
001 = 2 KB
011 = 8 KB
111 = DIMM0 not installed
Both banks 0 and 1 must have the same page size. When DIMM0 (neither bank 0 or 1) is not installed,
program all other DIMM0 fields to 0.
Reserved:
Set to 0.
11
10:8
RSVD
DIMM0_SZ
110 = 256 MB
111 = 512 MB (not supported)
7
RSVD
6:4
DIMM0_PG_SZ
3:0
RSVD
GX_BASE+840Ch-840Fh
MC_SYNC_TIM1 (R/W)
Default Value = 2A733225h
31
RSVD
LTMODE
Reserved:
Set to 0.
CAS Latency (LTMODE):
CAS latency is the delay, in SDRAM clock cycles, between the registration
of a read command and the availability of the first piece of output data. This parameter significantly
affects system performance. Optimal setting should be used. If DIMMs are used BIOS can interrogate
EEPROM across the I
2
C interface to determine this value:
000 = Reserved
010 = 2 CLK
100 = 4 CLK
001 = Reserved
011 = 3 CLK
101 = 5 CLK
This field will not take effect until SDRAMPRG (bit 0 of MC_MEM_CNTRL1) transitions from 0 to 1.
RFSH to RFSH/ACT Command Period (tRC):
Minimum number of SDRAM clock between RFSH
and RFSH/ACT commands:
0000 = Reserved
0100 = 5 CLK
1000 = 9 CLK
0001 = 2 CLK
0101 = 6 CLK
1001 = 10 CLK
0010 = 3 CLK
0110 = 7 CLK
1010 = 11 CLK
0011 = 4 CLK
0111 = 8 CLK
1011 = 12 CLK
ACT to PRE Command Period (tRAS):
Minimum number of SDRAM clocks between ACT and PRE
commands:
0000 = Reserved
0100 = 5 CLK
1000 = 9 CLK
0001 = 2 CLK
0101 = 6 CLK
1001 = 10 CLK
0010 = 3 CLK
0110 = 7 CLK
1010 = 11 CLK
0011 = 4 CLK
0111 = 8 CLK
1011 = 12 CLK
Reserved:
Set to 0.
PRE to ACT Command Period (tRP):
Minimum number of SDRAM clocks between PRE and ACT
commands:
000 = Reserved
010 = 2 CLK
100 = 4 CLK
001 = 1 CLK
011 = 3 CLK
101 = 5 CLK
Reserved:
Set to 0.
Delay Time ACT to READ/WRT Command (tRCD):
Minimum number of SDRAM clock between ACT
and READ/WRT commands. This parameter significantly affects system performance. Optimal setting
should be used:
000 = Reserved
010 = 2 CLK
100 = 4 CLK
001 = 1 CLK
011 = 3 CLK
101 = 5 CLK
Reserved:
Set to 0.
ACT(0) to ACT(1) Command Period (tRRD):
Minimum number of SDRAM clocks between ACT and
ACT command to two different component banks within the same module bank. The memory control-
ler does not perform back-to-back Activate commands to two different component banks without a
READ or WRT command between them. Hence, this field should be set to 001.
30:28
110 = 6 CLK
111 = 7 CLK
27:24
RC
1100 = 13 CLK
1101 = 14 CLK
1110 = 15 CLK
1111 = 16 CLK
23:20
RAS
1100 = 13 CLK
1101 = 14 CLK
1110 = 15 CLK
1111 = 16 CLK
19
RSVD
RP
18:16
110 = 6 CLK
111 = 7 CLK
15
RSVD
RCD
14:12
110 = 6 CLK
111 = 7 CLK
11
10:8
RSVD
RRD
Table 4-15. Memory Controller Registers (Continued)
Bit
Name
Description