Sharp LH79524 - Static Memory Configuration Register (Sconfigx); Table 7-52. Sconfigx Register; Table 7-53. Sconfigx Fields

External Memory Controller LH79524/LH79525 User’s Guide
7-52 Version 1.0
7.5.2.21 Static Memory Configuration Register (SCONFIGx)
The Static Memory Configuration Registers are used to configure the static memory
configuration.
These registers must only be modified during system initialization, or when there are
no current or outstanding transactions. Software can ensure that there are no current or
outstanding transactions by waiting until the memory controller is idle, then entering
Low-Power Mode (CONTROL:MODE = 1), or Disable Mode (CONTROL:ENABLE = 0).
When in these two modes, external memory access is not allowed, ensuring that
changing parameters will not corrupt external data. Low-Power Mode automatically
refreshes SDRAM; Disable Mode requires commanding the SDRAM to Self Refresh
(DYNMCTRL:SR = 1) prior to entering Disable.
NOTES:
1. The reset value for nCS1 changes depending on what byte lane boot state is selected. If nBLE0 isn’t driven
externally at reset, reset value will be 0. Other chip selects always have a reset value of 0.
2. The reset value for nCS1 changes accordingly to what boot mode width is selected. If nBLE2 and nBLE1
aren’t driven externally at reset, system will boot in 16-bit mode, with MW resetting to 0b01. Other chip
selects always have a reset value of 0b00.
Table 7-52. SCONFIGx Register
BIT 31 30 29 28 27 26 25 24 23 22 21 20 19 18 17 16
FIELD /// P B ///
RESET 0000000000000000
TYPE RO RO RO RO RO RO RO RO RO RO RO RW RW RW RW RW
BIT 15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 0
FIELD /// EW BLS
1
PC /// PM /// MW
2
RESET 0000000000000000
TYPE RW RW RW RW RW RW RW RW RW RW RW RW RW RW RW RW
ADDR
0xFFFF1000 + 0x200 for SCONFIG0
0xFFFF1000 + 0x220 for SCONFIG1
0xFFFF1000 + 0x240 for SCONFIG2
0xFFFF1000 + 0x260 for SCONFIG3
Table 7-53. SCONFIGx Fields
BITS NAME FUNCTION
31:21 /// Reserved Reading returns 0. Write the reset value.
20 P
Write Protect
1 = Write protected
0 = Not Write protected
19 B
Buffer Enable
1 = Read and write buffer enabled
0 = Read and write buffer disabled
18:9 /// Reserved Reading returns 0. Write the reset value.