LPDDR5 SDRAM is a high-speed synchronous DRAM device internally configured as 4Bank/4BG per channel. LPDDR5 SDRAM’s density is up to 32Gb.
These devices contain the following number of bits:
2Gb has 2,147,483,648 bits.
3Gb has 3,221,225,472 bits.
4Gb has 4,294,967,296 bits.
6Gb has 6,442,450,944 bits.
8Gb has 8,589,934,592 bits.
12Gb has 12,884,901,888 bits.
16Gb has 17,179,869,184 bits.
24Gb has 25,769,803,776 bits.
32Gb has 34,359,738,368 bits.
LPDDR5 devices use 1 or 2 clocks architecture on the Command/Address (CA) bus to reduce the number of input pins in the system. The 7 bit CA bus contains command, address, bank information and functional indicators. Each command uses 1 or 2 clock cycle, during which command information is transferred on the rising and the falling edge of the clock. See Command Truth Table for details.
These devices use double data rate architecture on the DQ pins to achieve high speed operation in WCK clocking system. The double data rate architecture is essentially 16n pre-fetch architecture with an interface designed to transfer two data bits per DQ every clock cycle at the I/O pins. A single read or write access for the LPDDR5 SDRAM effectively consists of a single 16n-bit wide, one clock cycle data transfer at the internal DRAM core and 16 corresponding n-bit wide, one half-clock-cycle data transfer at the I/O pins. Read and Write accesses to the LPDDR5 SDRAMs are burst oriented; accesses start a selected location and continue for a programmed number of locations in a programmed sequence. Accesses begin with the registration of an Activate command, which is followed by Read, Write or Mask Write command.
The address and BA bits registered coincident with the Activate command are used to select the row and the bank to be accessed. The address bits registered coincident with the Read, Write or Mask Write command are used to select the bank and the starting column location for the burst access.
Prior to normal operation, the LPDDR5 SDRAM is required to be initialized. The Power-Up, Initialization, and Power-off Procedure section provides detailed information covering device initialization.
