MC68HC908AZ32ACFU MOTOROLA [Motorola, Inc], MC68HC908AZ32ACFU Datasheet - Page 61

• Manufacturer Part Number: MC68HC908AZ32ACFU
• Description: Microcontrollers
• Manufacturer: MOTOROLA [Motorola, Inc]

Advance Information — 68HC908AZ32A
3.1 Contents
3.2 Introduction
3.3 Functional Description
68HC908AZ32A — Rev 0.0
MOTOROLA
NOTE:
3.2
3.3
This section describes the 1024 bytes of random-access memory
(RAM).
Addresses $0050 through $044F are RAM locations. The location of the
stack RAM is programmable with the reset stack pointer instruction
(RSP). The 16-bit stack pointer allows the stack RAM to be anywhere in
the 64K-byte memory space.
For correct operation, the stack pointer must point only to RAM
locations.
Within page zero are 176 bytes of RAM. Because the location of the
stack RAM is programmable, all page zero RAM locations can be used
for input/output (I/O) control and user data or code. When the stack
pointer is moved from its reset location at $00FF, direct addressing
mode instructions can access all page zero RAM locations efficiently.
Page zero RAM, therefore, provides ideal locations for frequently
accessed global variables.
Before processing an interrupt, the CPU uses five bytes of the stack to
save the contents of the CPU registers.
Freescale Semiconductor, Inc.
For More Information On This Product,
Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 61
Functional Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 61
Go to: www.freescale.com
RAM
Section 3. RAM
Advance Information
61