Selecting the Memory Device

The Fabric DDR subsystem supports DDR3, DDR3L, DDR4, and LPDDR3 memory devices.

The memory that is used with the system depends on the application requirements. No single memory device can fulfill all system requirements; therefore, the trade-offs associated with each memory type must be considered for a balanced design.

Consider the following factors while selecting the memory device:

Cost
Bandwidth and speed
Power consumption
Bus width
Latency
Capacity

The following table lists the memory parameters for DDR3, DDR3L, DDR4, and LPDDR3 memory devices. Based on the system requirements (bandwidth, speed, bus width, density, and cost), the appropriate memory device is selected.

Table 1. Memory Selection Parameters
Parameter	DDR3	DDR3L	DDR4	LPDDR3
DDR clock	666	666	800	666
Data width (in bits)	16, 32, 64	16, 32, 64	16, 32, 64	16, 32
Burst length (in bytes)	8	8	8	8
Number of banks	8	8	8,16	8
Density	512 Mb–8192 Mb	512 Mb–8192 Mb	2 Gb–16 Gb	32 Gb
I/O standard	SSTL-15 Class I, II	SSTL-135 Class I, II	POD-12 Class I, II^*	HSUL-12

Note: HSTL_12 IO standard is used for DDR4 address, command, and control signals.