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Zynq-7000 AP SoC Technical Reference Manual www.xilinx.com 1719
UG585 (v1.11) September 27, 2016
Appendix B: Register Details
Register DDRIOB_CLOCK Details
Field Name Bits Type Reset Value Description
reserved 31:12 rw 0x0 Reserved
PULLUP_EN 11 rw 0x1 enables pullup on output
0: no pullup
1: pullup enabled
OUTPUT_EN 10:9 rw 0x0 Enables output mode to enable output ties to
00: ibuf
01 and 10: reserved
11: obuf
TERM_DISABLE_MO
DE
8 rw 0x0 Termination is used during read transactions and
may be disabled (automatically by hardware)
when there are no reads taking place through the
DDR Interface. Disabling termination reduces
power consumption.
0: termination always enabled
1: use 'dynamic_dci_ts' to disable termination
when not in use
NOTE: This bit must be 0 during DRAM
init/training. It may be set to 1 after init/training
completes.
IBUF_DISABLE_MOD
E
7 rw 0x0 Use ibuf_disable_into control ibuf
0: ibuf is enabled
1: use ibuf_disable_in_to control enable
NOTE: This must be 0 during DRAM
init/training and can only be set to 1 after
init/training completes.
DCI_TYPE 6:5 rw 0x0 DCI Mode Selection:
00: DCI Disabled (DDR2/3L ADDR and CLOCK)
01: DCI Drive (LPDDR2)
10: reserved
11: DCI Termination (DDR2/3/3L DATA and
DIFF)
TERM_EN 4 rw 0x0 Tri State Termination Enable:
0: disable
1: enable
DCI_UPDATE_B 3 rw 0x0 DCI Update Enable:
0: disable
1: enable