Cirrus Logic CS4953xx - Manual (Page 85)

8-7 Copyright 2010 Cirrus Logic, Inc. DS732UM10
SDRAM/Flash Controller Interface
CS4953xx Hardware User’s Manual
DynamictRFC
Configure the auto refresh period and auto refresh to active command
time. Also known as Trrc
Bit 31:5 = 0 = Reserved
Bit 4:0 = Trc, where:
0x0 to 0xE = (n + 1) DSP clk cycles.
0x1F = 32 DSP clk cycles.
Example:
Trc = 65 nS, HCLK = 120Mhz
Trc = 65 nS * 120 Mhz -1=7.8-1 = 0x7
0x81000069
0xHHHHHHHH
Default 0x00000007
DynamictXSR
Configure the exit self refresh to active command time.
Bit 31:5 = 0 = Reserved
Bit 4:0 = Txsr, where:
0x0 to 0x1E = (n + 1) DSP clk cycles.
0x1F = 32DSP clk cycles.
Example:
Txsr = 83 nS, HCLK = 120Mhz
Txsr = 83 nS * 120 Mhz-1 =10-1 = 0x9
0x8100006A
0xHHHHHHHH
Default 0x00000009
DynamictRRD
Configure the active bank A to active bank B latency
Bit 31:4 = 0 = Reserved
Bit 3:0 = Trrd, where:
0x0 to 0xE = (n + 1) DSP clk cycles.
0xF= 16 DSP clk cycles.
Example:
Trrd = 15 nS, HCLK = 120Mhz
Trrd = 15 nS * 120 Mhz - 1= 1.8 - 1 = 0x1
0x8100006B
0xHHHHHHHH
Default 0x00000001
DynamictMRD
Configure the load mode register to active command time. Also known as
Trsa
Bit 31:4 = 0 = Reserved
Bit 3:0 = Tmrd, where:
0x0 to 0xE = (n + 1) DSP clk cycles.
0xF= 16 DSP clk cycles.
Example:
Tmrd = 1CLKs, HCLK = 120Mhz
Tmrd = 1-1 = 0x0
0x8100006C
0xHHHHHHHH
Default 0x00000000
DynamicConfig0
Configure the active bank A to active bank B latency
Bit 31:12 = 0 = Reserved
Bit 11:7 = External bus address mapping (Row, Bank, Column),where:
00001 = 16Mb (1Mx16), 2 banks, row length = 11, column length = 8
00101 = 64Mb (4Mx16), 4 banks, row length = 12, column length = 8
01001 = 128Mb (8Mx16), 4 banks, row length = 12, column length = 9
Bit 6:0 = 0 = Reserved
0x8100006E
0xHHHHHHHH
Default 0x00000280
Table 8-2. SDRAM/Flash Controller Parameters (Continued)
Mnemonic Hex Message