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Zynq-7000 AP SoC Technical Reference Manual www.xilinx.com 854
UG585 (v1.11) September 27, 2016
Appendix B: Register Details
Register (ddrc) DRAM_disable_DQ
Register DRAM_disable_DQ Details
reg_ddrc_post_cke_x10
24
25:16 rw 0x2 Clock cycles to wait after driving CKE high to
start the DRAM initialization sequence.
Units: 1024 clocks.
DDR2 typically require a 400 ns delay, requiring
this value to be programmed to 2 at all clock
speeds. LPDDR2 - Typically require this to be
programmed for a delay of 200 us.
reserved 15:14 ro 0x0 Reserved
reg_ddrc_pre_cke_x102
4
13:4 rw 0x3 Clock cycles to wait after a DDR software reset
before driving CKE high to start the DRAM
initialization sequence.
Units: 1024 clock cycles.
DDR2 Specifications typically require this to be
programmed for a delay of >= 200 uS.
LPDDR2 - tINIT0 of 20 mS (max) + tINIT1 of 100
nS (min)
reg_ddrc_burst_rdwr 3:0 rw 0x4 Controls the burst size used to access the DRAM.
This must match the BL mode register setting in
the DRAM.
0010: Burst length of 4
0100: Burst length of 8
1000: Burst length of 16 (LPDDR2 with 16-bit
data)
All other values are reserved
Name DRAM_disable_DQ
Relative Address 0x00000038
Absolute Address 0xF8006038
Width 13 bits
Access Type mixed
Reset Value 0x00000000
Description DRAM Disable DQ
Field Name Bits Type Reset Value Description
Field Name Bits Type Reset Value Description
reserved 12:9 rw 0x0 Reserved. Do not modify.
reserved 8 rw 0x0 Reserved. Do not modify.
reserved 7 rw 0x0 Reserved. Do not modify.