
MC68F375
STATIC RANDOM ACCESS MEMORY (SRAM)
MOTOROLA
REFERENCE MANUAL
Rev. 25 June 03
11-1
SECTION 11
STATIC RANDOM ACCESS MEMORY (SRAM)
11.1 Introduction
This SRAM module is a fast access (two clocks) general purpose 8K (8,192 bytes)
static RAM (SRAM) for the MCU and is accessed via the IMB3. In addition there is 2K
(configured as four blocks of 512 bytes each) of patch static RAM. These modules are
fast access (two clocks) general purpose static RAM (SRAM) for the MCU with a patch
option which provides a method to overlay the internal CMFI memory for emulation.
As an additional feature, the 512-byte arrays can be used as additional SRAM. A reg-
ister map showing the SRAM and overlay configuration registers and memory blocks
The SRAM module is powered by VDDL in normal operation and may be used as
standby SRAM if standby power is supplied via the VSTBY pin of the MCU. Switching
between VDDL and VSTBY will occur automatically.
When used as general purpose SRAM, this module is accessed via the IMB3. The
SRAM may be read or written as either bytes or words. Access for aligned long-word
operations is supported by back-to-back IMB3 accesses (four clocks) to accommodate
32-bit operations.
11.2 Programmer’s Model
Each SRAM module consists of two separately addressable sections. The first is a set
of memory mapped control and status registers used for configuration and testing of
the SRAM array. The second section is the array itself.
11.2.1 SRAM Control Block
There are four registers provided for configuration and control of each SRAM module:
SRAM module configuration register (RAMMCR), a factory test register (RAMTST),
and the array base address registers (RAMBAH, RAMBAL). In order to offer the max-
imum protection for the SRAM array, the SRAM module control registers are located
in supervisor data space.
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Freescale Semiconductor, Inc.
For More Information On This Product,
Go to: www.freescale.com
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