Xilinx Zynq-7000

Zynq-7000 AP SoC and 7 Series FPGAs MIS v4.1 93
UG586 November 30, 2016
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Chapter 1: DDR3 and DDR2 SDRAM Memory Interface Solution
app_addr[ADDR_WIDTH – 1:0]
This input indicates the address for the request currently being submitted to the UI. The UI
aggregates all the address fields of the external SDRAM and presents a flat address space to
you.
app_cmd[2:0]
This input specifies the command for the request currently being submitted to the UI. The
available commands are shown in Table 1-18.
app_ref_req Input
This active-High input requests that a refresh command be
issued to the DRAM.
app_ref_ack Output
This active-High output indicates that the Memory Controller
has sent the requested refresh command to the PHY interface.
app_zq_req Input
This active-High input requests that a ZQ calibration command
be issued to the DRAM.
app_zq_ack Output
This active-High output indicates that the Memory Controller
has sent the requested ZQ calibration command to the PHY
interface.
ui_clk Output This UI clock must be a half or quarter of the DRAM clock.
init_calib_complete Output PHY asserts init_calib_complete when calibration is finished.
app_ecc_multiple_err[7:0]
(1)
Output
This signal is applicable when ECC is enabled and is valid along
with app_rd_data_valid. The app_ecc_multiple_err[3:0] signal is
non-zero if the read data from the external memory has two bit
errors per beat of the read burst. The SECDED algorithm does
not correct the corresponding read data and puts a non-zero
value on this signal to notify the corrupted read data at the UI.
ui_clk_sync_rst Output This is the active-High UI reset.
app_ecc_single_err[7:0] Output
This signal is applicable when ECC is enabled and is valid along
with app_rd_data_vali. The app_ecc_single_err signal is
non-zero if the read data from the external memory has a single
bit error per beat of the read burst.
Notes:
1. This signal is brought up to the memc_ui_top module level only. This signal should only be used when ECC is enabled.
Table 1-17: User Interface (Cont’d)
Signal Direction Description
Table 1-18: Commands for app_cmd[2:0]
Operation app_cmd[2:0] Code
Read 001
Write 000
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