mcf51ac256a Freescale Semiconductor, Inc, mcf51ac256a Datasheet - Page 494

• Manufacturer Part Number: mcf51ac256a
• Description: Mcf51ac Flexis
• Manufacturer: Freescale Semiconductor, Inc

Version 1 ColdFire Debug (CF1_DEBUG)
22.1.1
Debug support is divided into three areas:
22-2
•
•
Background debug mode (BDM)—Provides low-level debugging in the ColdFire processor core.
In BDM, the processor core is halted and a variety of commands can be sent to the processor to
access memory, registers, and peripherals. The external emulator uses a one-pin serial
communication protocol. See
Real-time debug support—Use of the full BDM command set requires the processor to be halted,
which many real-time embedded applications cannot support. The core includes a variety of
internal breakpoint registers which can be configured to trigger and generate a special interrupt.
The resulting debug interrupt lets real-time systems execute a unique service routine that can
quickly save the contents of key registers and variables and return the system to normal operation.
The external development system can then access the saved data, because the hardware supports
IPL_B[2:0]
RESET
Overview
BKGD
MCF51AC256 ColdFire Integrated Microcontroller Reference Manual, Rev. 5
Figure 22-1. Simplified Version 1 ColdFire Core Block Diagram
Version 1 ColdFire Core (CF1Core)
PST[3:0]/DDATA[3:0]
IFP
OEP
BDC
CFxBDM
PST/DDATA — Processor status/debug data
RTD
Central Processing Unit
(CF1Cpu)
Debug
(CF1Dbg)
Visibility Bus
BDC
Section 22.4.1, “Background Debug Mode (BDM)”.
— Instruction fetch pipeline
— Operand execution pipeline
— Background debug controller
— ColdFire background debug module
— Real-time debug
BDM
CFx
OEP
DDATA
IFP
RTD
PST/
Freescale Semiconductor
wdata
addr
rdata
attb