XC2000 datasheet(76/647 Pages) INFINEON

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XC2000 Derivatives

System Units (Vol. 1 of 2)

Memory Organization

Preliminary

User’s Manual

3-14

V1.0, 2007-06

MemoryX2K, V1.1

3.5

System Stack

The system stack may be defined anywhere within the XC2000’s memory areas

(including external memory).

For all system stack operations the respective stack memory is accessed via a 24-bit

stack pointer. The Stack Pointer (SP) register provides the lower 16 bits of the stack

pointer (stack pointer offset), the Stack Pointer Segment (SPSEG) register adds the

upper 8 bits of the stack pointer (stack segment). The system stack grows downward

from higher towards lower locations as it is filled. Only word accesses are supported to

the system stack.

incremented after data has been pulled from the system stack. Only word accesses are

supported to the system stack.

By using register SP for stack operations, the size of the system stack is limited to

64 KBytes. The stack must be located in the segment defined by register SPSEG.

The stack pointer points to the latest system stack entry, rather than to the next available

system stack address.

A stack overflow (STKOV) register and a stack underflow (STKUN) register are provided

to control the lower and upper limits of the selected stack area. These two stack

boundary registers can be used both for protection against data corruption.

For best performance it is recommended to locate the stack to the DPRAM or to the

DSRAM. Using the DPRAM may conflict with register banks or MAC operands.

XC2000 Datasheet(PDF) 76 Page - Infineon Technologies AG