M65KA512AB datasheet(6/55 Pages) STMICROELECTRONICS

6 / 55 page

Description

M65KA512AB

6/55

Description

The M65KA512AB is a 512 Mbit Low Power Synchronous DRAM (SDRAM). The memory

array is organized as 4 Banks of 8,388,608 words of 16 bits each.

The LPSDRAM achieves low power consumption and high-speed data transfer using the

pipeline architecture.

The device architecture is illustrated in Figure 2: Functional block diagram. It uses Burst

mode to read and write data. It is capable of one, two, four, eight-word and full-page,

sequential and interleaved Burst.

To minimize current consumption during self-refresh operations, the M65KA512AB includes

three mechanisms configured via the Extended Mode Register:

●

Automatic Temperature Compensated Self Refresh (ATCSR) used to adapt the refresh

time according to the operating temperature (see Table 5: Extended mode Register

definition)

●

Partial Array Self Refresh (PASR) performs a limited refresh of part of the PSRAM

memory array. This area can be configured to half bank, a quarter of bank, one bank,

two banks or all banks. This mechanism allows to reduce the device Standby current by

refreshing only the part of the memory array that contains essential data.

●

The Deep Power-Down (DPD) mode completely halts the refresh operation and

achieves minimum current consumption by cutting off the supply voltage from the

whole memory array.

The device is programmable through two registers, the Mode Register and the Extended

Mode Register:

●

The Mode Register is used to select the CAS Latency, the Burst Type (sequential,

interleaved) and the Burst Length (1-, 2-, 4-, 8-word width or full page) through

programming the A6 to A4 bits, the A3 bit and the A2 to A0 bits, respectively (see

Table 4).

●

The Extended Mode Register is used to program the low-power features (PASR,

ATCSR) and Driver Strength) to reduce the current consumption during the Self

Refresh operations. For more details, refer to Table 5: Extended mode Register

definition, and to Section 4.2: Extended Mode Register Set command.

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