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Zynq-7000 AP SoC Technical Reference Manual www.xilinx.com 294
UG585 (v1.11) September 27, 2016
Chapter 10: DDR Memory Controller
10.1.5 DDR Memory Types, Densities, and Data Widths
The DDR memory controller is able to connect to devices under the conditions identified in
Table 10-1.
Table 10-2 provides a collection of example memory configurations.
10.1.6 I/O Signals
The DDR signal pins are listed in Table 10-3. The DDR I/O buffers are powered by the VCC_DDR
power pins. The I/O state (including initial state) of the DDR signals is controlled via registers:
slcr.DDRIOB_ADDR0
slcr.DDRIOB_ADDR1
slcr.DDRIOB_DATA0
slcr.DDRIOB_DATA1
slcr.DDRIOB_DIFF0
slcr.DDRIOB_DIFF1
slcr.DDRIOB_CLOCK
The output characteristics are controlled by the following registers and are reserved to specific
values produced by Xilinx tools:
slcr.DDRIOB_DRIVE_SLEW_ADDR
Table 10-1: Connectivity Limitations
Parameter Value Notes
Maximum Total Memory Density 1 GB 1 GB of address map is allocated to DRAM
Total Data Width (bits) 16, 32 ECC can only use a 32-bit configuration: 16 data bits, 10
check bits
Component Data Width (bits) 8, 16, 32 4-bit devices are not supported
Maximum Ranks 1
Maximum Row Address (bits) 15
Maximum Bank Address (bits) 3
Table 10-2: Example Memory Configurations
Technology
Component
Configuration
Number of
Components
Component
Density
Total Width Total Density
DDR3/DDR3L x16 2 4 Gb 32 1 GB
DDR2 x8 4 2 Gb 32 1 GB
LPDDR2 x32 1 2 Gb 32 256 MB
LPDDR2 x16 2 4 Gb 32 1 GB
LPDDR2 x16 1 2 Gb 16 256 MB