Supported Platforms: MOD5441x

Example program for ColdFire MCF5441x Rapid GPIO capability on the MOD5441x core module.

The RGPIO module provides 16-bits of high-speed GPIO functionality, mapped to the processor’s bus. The key features of this module include:

16 bits of high-speed GPIO functionality connected to the processor’s local 32-bit bus
Memory-mapped device connected to the ColdFire core’s local bus
Support for all access sizes: byte, word, and longword
All reads and writes complete in a single data phase cycle for zero wait-state response
Data bits can be accessed directly or via alternate addresses to provide set, clear, and toggle functions
Alternate addresses allow set, clear, toggle functions using simple store operations without the need for read-modify-write references
Unique data direction and pin enable control registers
Pin toggle rates typically 1.5–3.5x faster than comparable pin mapped onto peripheral bus

This example:

Toggles RGPIO signal 0 (module pin 37) 50 times as fast as possible at 1 second intervals.
The time from rising edge to rising edge of a pulse measures 16ns (62.5MHz).
The processor slew rate must be set to maximum to acheive a speed this fast and you will
need a fast scope and probe with a very short (1 inch) ground connection to measure it.

There are 3 functions illustrating the various methods to create the pulses in order of fastest to slowest: