RM0345 datasheet(12/38 Pages) STMICROELECTRONICS

12 / 38 page

Calibration bus interface and External Memory

RM0345

12/38

Doc ID 024080 Rev 3

Calibration bus interface and External Memory

The SPC563M64xx features a 16-bit de-multiplexed calibration bus interface that is

connected to an external 2Mbyte SRAM thanks to an on board latch.

4.1

External memory specification

The

calibration board provides a SRAM with the following characteristics:

–

2Mbyte static RAMs organized as 1024K words by 16 bits;

–

16-bit data width;

–

Fully static operation: no clock or refresh required;

–

3.3V input supply;

–

/CE power-down;

–

High-speed access time (10ns);

–

Full automotive temperature range;

–

Lead-free.

When /CE is HIGH (deselected), the device assumes a standby mode at which the power

dissipation can be reduced down with CMOS input levels.

4.2

SRAM supply and data retention function

The circuitry in Figure 6 has been implemented on the

calibration board to protect the

memory and to guarantee that the Working Page is valid after a power fail of the target

application by putting the SRAM in standby powered.

The 3.3 V supply of the SRAM (Vmem) is gated by the RESET and RSTOUT signals of the

SPC563M64xx.

The memory enable is driven via the SPC563M64xx chip select C_CS0 “and” the RESETs

signals combination.

RM0345 Datasheet(PDF) 12 Page - STMicroelectronics