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System Memory Controller (SMC)
3
Error_Address RegisterERROR_ADDRESS These bits reflect the value that corresponds to bits 0-28 of the PPC60x address bus when the SMC last logged an error during a PowerPC access to SDRAM. They reflect the value of the SCRUB ADDRESS counter if the error was logged during a scrub cycle.Scrub/Refresh Registerscb0, scb1 These bits increment every time the scrubber completes a scrub of the entire SDRAM. When they reach binary 11, they roll over to binary 00 and continue. These bits are cleared by power-up reset.swen When set, swen allows the scrubber to perform write cycles. When cleared, swen prevents scrubber writes.SCRUB_FREQUENCY Determines the rate of scrubbing by settin g the roll-over count for the scrub prescale counter. Each time the SMC performs a refresh burst, the scrub prescale counter increments by one. When the scrub prescale counter reaches the value stored in this register, it clears a nd resumes counting starting at 0.
Address $FEF80038
Bit
0
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
Name ERROR_ADDRESS
0
0
0
Operation READ ONLY
R
R
R
Reset 0 P
X
X
X
Address $FEF80040
Bit
0
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
Name
scb0
scb1
0
0
0
0
0
swen
SCRUB FREQUENCY
Operation
R
R
R
R
R
R
R
R/W
READ ZERO READ ZERO READ/WRITE
Reset
0 P
0 P
X
X
X
X
X
0 P
X X $00 P