
II CORE BLOCK: BCU (Bus Control Unit)
S1C33T01 FUNCTION PART
EPSON
B-II-4-45
RPRC1–RPRC0: Number of RAS precharge cycles (D[7:6]) / DRAM timing set-up register (0x48130)
Select the number of precharge cycles during a DRAM access.
Table 4.29
Number of RAS Precharge Cycles
RPRC1
RPRC0
Number of cycles
1
4 cycles
1
0
3 cycles
0
1
2 cycles
0
1 cycle
The contents set here are applied to all of areas 14, 13, 8, and 7 that are set for DRAM.
At cold start, RPRC is set to "0" (1 cycle). At hot start, RPRC retains its status before being initialized.
CASC1–CASC0: Number of CAS cycles (D[4:3]) / DRAM timing set-up register (0x48130)
Select the number of CAS cycles during a DRAM access.
Table 4.30
Number of CAS Cycles
CASC1
CASC0
Number of cycles
1
4 cycles
1
0
3 cycles
0
1
2 cycles
0
1 cycle
The contents set here are applied to all of areas 14, 13, 8, and 7 that are set for DRAM.
At cold start, CASC is set to "0" (1 cycle). At hot start, CASC retains its status before being initialized.
RASC1–RASC0: Number of RAS cycles (D[1:0]) / DRAM timing set-up register (0x48130)
Select the number of RAS cycles during a DRAM access.
Table 4.31
Number of RAS Cycles
RASC1
RASC0
Number of cycles
1
4 cycles
1
0
3 cycles
0
1
2 cycles
0
1 cycle
The contents set here are applied to all of areas 14, 13, 8, and 7 that are set for DRAM.
At cold start, RASC is set to "0" (1 cycle). At hot start, RASC retains its status before being initialized.
A18IO: Areas 18–17 internal/external access selection (DF) / Access control register (0x48132)
A16IO: Areas 16–15 internal/external access selection (DE) / Access control register (0x48132)
A14IO: Areas 14–13 internal/external access selection (DD) / Access control register (0x48132)
A12IO: Areas 12–11 internal/external access selection (DC) / Access control register (0x48132)
A8IO: Areas 8–7 internal/external access selection (DA) / Access control register (0x48132)
A6IO: Area 6 internal/external access selection (D9) / Access control register (0x48132)
A5IO: Areas 5–4 internal/external access selection (D8) / Access control register (0x48132)
Select either internal access or external access for each area.
Write "1": Internal access
Write "0": External access
Read: Valid
When AxxIO is set to "1", the internal device that mapped to the corresponding area is accessed. When AxxIO is set
to "0", the external device is accessed.
At cold start, these bits are set to "0" (external access). At hot start, these bits retain their status before being
initialized.