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Zynq-7000 AP SoC Technical Reference Manual www.xilinx.com 873
UG585 (v1.11) September 27, 2016
Appendix B: Register Details
Register CHE_REFRESH_TIMER01 Details
Register (ddrc) CHE_T_ZQ
Register CHE_T_ZQ Details
Access Type rw
Reset Value 0x00008000
Description CHE_REFRESH_TIMER01
Field Name Bits Type Reset Value Description
reserved 23:12 rw 0x8 Reserved. Do not modify.
reserved 11:0 rw 0x0 Reserved. Do not modify.
Name CHE_T_ZQ
Relative Address 0x000000A4
Absolute Address 0xF80060A4
Width 32 bits
Access Type rw
Reset Value 0x10300802
Description ZQ parameters
Field Name Bits Type Reset Value Description
reg_ddrc_t_zq_short_n
op
31:22 rw 0x40 DDR2: not applicable.
LPDDR2 and DDR3: Number of cycles of NOP
required after a ZQCS (ZQ calibration short)
command is issued to DRAM. Units: Clock cycles.
reg_ddrc_t_zq_long_n
op
21:12 rw 0x300 DDR2: not applicable.
LPDDR2 and DDR3: Number of cycles of NOP
required after a ZQCL (ZQ calibration long)
command is issued to DRAM. Units: Clock cycles.
reg_ddrc_t_mod 11:2 rw 0x200 Mode register set command update delay
(minimum d'128)
reg_ddrc_ddr3 1 rw 0x1 Indicates operating in DDR2/DDR3 mode.
Default value is set for DDR3.
reg_ddrc_dis_auto_zq 0 rw 0x0 1=disable controller generation of ZQCS
command. Co_gs_zq_calib_short can be used
instead to control ZQ calibration commands.
0=internally generate ZQCS commands based on
reg_ddrc_t_zq_short_interval_x1024. This is only
present for implementations supporting DDR3
and LPDDR2 devices.