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Zynq-7000 AP SoC Technical Reference Manual www.xilinx.com 871
UG585 (v1.11) September 27, 2016
Appendix B: Register Details
Register ctrl_reg5 Details
Field Name Bits Type Reset Value Description
reserved 31:26 ro 0x0 Reserved
reg_ddrc_t_ckesr 25:20 rw 0x4 Minimum CKE low width for Self Refresh entry to
exit Timing in memory clock cycles.
Recommended settings:
LPDDR2: tCKESR
DDR2: tCKE
DDR3: tCKE+1
reg_ddrc_t_cksrx 19:16 rw 0x5 This is the time before Self Refresh Exit that CK is
maintained as a valid clock before issuing SRX.
Specifies the clock stable time before SRX.
Recommended settings:
LPDDR2: 2
DDR2: 1
DDR3: tCKSRX
reg_ddrc_t_cksre 15:12 rw 0x5 This is the time after Self Refresh Entry that CK is
maintained as a valid clock. Specifies the clock
disable delay after SRE.
Recommended settings:
LPDDR2: 2
DDR2: 1
DDR3: tCKSRE
reg_ddrc_dfi_t_dram_c
lk_enable
11:8 rw 0x1 Specifies the number of DFI clock cycles from the
de-assertion of the ddrc_dfi_dram_clk_disable
signal on the DFI until the first valid rising edge of
the clock to the DRAM memory devices at the
PHY-DRAM boundary. If the DFI clock and the
memory clock are not phase aligned, this timing
parameter should be rounded up to the next
integer value.
reg_ddrc_dfi_t_dram_c
lk_disable
7:4 rw 0x1 Specifies the number of DFI clock cycles from the
assertion of the ddrc_dfi_dram_clk_disable signal
on the DFI until the clock to the DRAM memory
devices, at the PHY-DRAM boundary, maintains a
low value. If the DFI clock and the memory clock
are not phase aligned, this timing parameter
should be rounded up to the next integer value.
reg_ddrc_dfi_t_ctrl_del
ay
3:0 rw 0x1 Specifies the number of DFI clock cycles after an
assertion or deassertion of the DFI control signals
that the control signals at the PHY-DRAM
interface reflect the assertion or de-assertion. If
the DFI clock and the memory clock are not
phase-aligned, this timing parameter should be
rounded up to the next integer value.