Datasheet

MC9S12XE-Family Reference Manual Rev. 1.25
Freescale Semiconductor 353
Chapter 10
XGATE (S12XGATEV3)
10.1 Introduction
The XGATE module is a peripheral co-processor that allows autonomous data transfers between the
MCU’s peripherals and the internal memories. It has a built in RISC core that is able to pre-process the
transferred data and perform complex communication protocols.
The XGATE module is intended to increase the MCU’s data throughput by lowering the S12X_CPU’s
interrupt load.
Figure 10-1 gives an overview on the XGATE architecture.
This document describes the functionality of the XGATE module, including:
• XGATE registers (Section 10.3, “Memory Map and Register Definition”)
• XGATE RISC core (Section 10.4.1, “XGATE RISC Core”)
• Hardware semaphores (Section 10.4.4, “Semaphores”)
• Interrupt handling (Section 10.5, “Interrupts”)
• Debug features (Section 10.6, “Debug Mode”)
• Security (Section 10.7, “Security”)
• Instruction set (Section 10.8, “Instruction Set”)
10.1.1 Glossary of Terms
XGATE Request
A service request from a peripheral module which is directed to the XGATE by the S12X_INT
module (see Figure 10-1). Each XGATE request attempts to activate a XGATE channel at a certain
priority level.
XGATE Channel
The resources in the XGATE module (i.e. Channel ID number, Priority level, Service Request
Vector, Interrupt Flag) which are associated with a particular XGATE Request.
Table 10-1. Revision History
Revision
Number
Revision Date
Sections
Affected
Description of Changes
V03.22 06 Oct 2005 - Internal updates
V03.23 14 Dec 2005
10.9.2/10-463 - Updated code example
V03.24 17 Jan 2006
- Internal updates