MC9S08QE128 MCU Series Reference Manual, Rev. 2
Freescale Semiconductor 321
Chapter 18
Debug Module (DBG)
(128K)
18.1 Introduction
The DBG module implements an on-chip ICE (in-circuit emulation) system and allows non-intrusive
debug of application software by providing an on-chip trace buffer with flexible triggering capability. The
trigger also can provide extended breakpoint capacity. The on-chip ICE system is optimized for the HCS08
8-bit architecture and supports 64K bytes or 128K bytes of memory space.
18.1.1 Features
The on-chip ICE system includes these distinctive features:
• Three comparators (A, B, and C) with ability to match addresses in 128K space
— Dual mode, Comparators A and B used to compare addresses
— Full mode, Comparator A compares address and Comparator B compares data
— Can be used as triggers and/or breakpoints
— Comparator C can be used as a normal hardware breakpoint
— Loop1 capture mode, Comparator C is used to track most recent COF event captured into FIFO
• Tag and Force type breakpoints
• Nine trigger modes
—A
— A Or B
— A Then B
— A And B, where B is data (Full mode)
— A And Not B, where B is data (Full mode)
— Event Only B, store data
— A Then Event Only B, store data
— Inside Range, A ≤ Address ≤ B
— Outside Range, Address < Α or Address > B
• FIFO for storing change of flow information and event only data
— Source address of conditional branches taken
— Destination address of indirect JMP and JSR instruction
— Destination address of interrupts, RTI, RTC, and RTS instruction
— Data associated with Event B trigger modes
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