Motorola MC9S12DP256, CML12S-DP256 manual BDM Operation, Autostart, Clock frequency = 24MHz

C M L 1 2 S D P 2 5 6 0 7 / 1 7 / 0 2

The CML12S-DP256 provides the NOICE debug monitor kernel as a subset of the MON12 monitor in reserved flash memory. User may apply the NOICE development system by setting the MON12 Autostart for the $F800 vector, reset the board and launch the NOICE host software on the PC. The NOICE monitor kernel applies the same resources, memory map, and ram interrupt table as the MON12 monitor. NOICE operation notes:

Baud Rate = 19.2K baud 8/n/1

E clock frequency = 24MHz

BDM OPERATION

The CML12S-DP256 board will emulate supported HC12 device internal flash memory in external ram. This feature allows BDM (Background Debug Modules) such as the AX-BDM12 to load and control the execution of code being developed without the necessity of the internal flash memory being programmed many times during the development process. This feature improves updating time and allows the use of may software breakpoints instead of being limited to only 2 hardware breakpoints.

Operation Notes for BDM use:

1)CML12S-DP256 MODC Option Jumper should be installed if a BDM is connected to the BDM Port. Default Mode is single-chip so the MODC option installed will force Special Single-chip Mode on Reset.

2)The BDM initialization of the HC12 should set the correct operating MODE (Expanded Wide for memory access). The EME, EMK, LSTRB, RW, ROMEN and Stretch configuration bits should be set for proper external memory access operation. The Axiom support CD contains sample set-up macros for the AX-BDM12.

3)While using the BDM, the user has full control over the memory map and hardware resources of the HCS12. The no resources are required to be reserved for monitor use and the user can apply the actual HCS12 interrupt vector table located at 0xFF8C - 0xFFFF.

AUTOSTART

The MON12 Monitor allows an Autostart operation to launch user applications programmed into the HCS12 internal flash fixed page ($3E) addresses 0x4000 - 0x7FFF from Reset. The Autostart mask and vector are stored in the nonvolatile internal EEprom at addresses $FEC - $FEF. The monitor provides special commands, AUTO and NOAUTO, to enable and disable the Autostart on the next Reset sequence. After an Autostart is enabled with a valid user vector, user application code will be started after Reset instead of the monitor or utility programs. To recover monitor operation after Autostart has been enabled, the AUTO OFF (Spare option on Revision C boards) option jumper can be installed or a low level applied to the XIRQ signal and Reset applied.

12