Motorola DSP Developer's Kit

sum-r.asm

y = mot###_sum(X)

Description

This function returns the sum of the element of real input vector X

Input/Output

Input: Vector X (real data)

Output: y (the sum of the element of X)

Algorithm

y = 0;
for(i=0; i<size; i++)
{
    y += X[i];
}                   

Memory & Register

Memory allocation:

• X memory: IN stores the address of the input of real vector X.

Register usage:

• Register A is used for the result
• Register R7 is used for the number of items in the array

Status Register

The assembly function sum-r.asm does not explicitly set any status registers/bits during the function execution.

Data Size Limit

The length of vector X can't be larger than the continuous available data memory size.

Data Range Limit

The value of input vector X must be between -1.0 and +1.0.

Precision

In the case of DSP563, precision is 23 bits.

In the case of DSP566, precision is 15 bits.

Performance Limit

DSP563:

DSP566:

sqrt-c.asm

sum-c.asm