Development Support
MC9S08QL8 MCU Series Reference Manual, Rev. 1
226
NXP Semiconductors
16.1.3
Features
Features of the BDC module include:
•
Single pin for mode selection and background communications
•
BDC registers are not located in the memory map
•
SYNC command to determine target communications rate
•
Non-intrusive commands for memory access
•
Active background mode commands for CPU register access
•
GO and TRACE1 commands
•
BACKGROUND command can wake CPU from stop or wait modes
•
One hardware address breakpoint built into BDC
•
Oscillator runs in stop mode, if BDC enabled
•
COP watchdog disabled while in active background mode
16.2
Background Debug Controller (BDC)
All MCUs in the HCS08 Family contain a single-wire background debug interface that supports in-circuit
programming of on-chip nonvolatile memory and sophisticated non-intrusive debug capabilities. Unlike
debug interfaces on earlier 8-bit MCUs, this system does not interfere with normal application resources.
It does not use any user memory or locations in the memory map and does not share any on-chip
peripherals.
BDC commands are divided into two groups:
•
Active background mode commands require that the target MCU is in active background mode (the
user program is not running). Active background mode commands allow the CPU registers to be
read or written, and allow the user to trace one user instruction at a time, or GO to the user program
from active background mode.
•
Non-intrusive commands can be executed at any time even while the user’s program is running.
Non-intrusive commands allow a user to read or write MCU memory locations or access status and
control registers within the background debug controller.
Typically, a relatively simple interface pod is used to translate commands from a host computer into
commands for the custom serial interface to the single-wire background debug system. Depending on the
development tool vendor, this interface pod may use a standard RS-232 serial port, a parallel printer port,
or some other type of communications such as a universal serial bus (USB) to communicate between the
host PC and the pod. The pod typically connects to the target system with ground, the BKGD pin, RESET,
and sometimes V
DD
. An open-drain connection to reset allows the host to force a target system reset,
which is useful to regain control of a lost target system or to control startup of a target system before the
on-chip nonvolatile memory has been programmed. Sometimes V
DD
can be used to allow the pod to use
power from the target system to avoid the need for a separate power supply. However, if the pod is powered
separately, it can be connected to a running target system without forcing a target system reset or otherwise
disturbing the running application program.
Содержание MC9S08QL4
Страница 4: ...MC9S08QL8 MCU Series Reference Manual Rev 1 4 NXP Semiconductors...
Страница 24: ...Chapter 2 Pins and Connections MC9S08QL8 MCU Series Reference Manual Rev 1 24 NXP Semiconductors...
Страница 36: ...Chapter 3 Modes of Operation MC9S08QL8 MCU Series Reference Manual Rev 1 36 NXP Semiconductors...
Страница 56: ...Chapter 4 Memory MC9S08QL8 MCU Series Reference Manual Rev 1 56 NXP Semiconductors...
Страница 120: ...Analog Comparator S08ACMPVLPV1 MC9S08QL8 MCU Series Reference Manual Rev 1 120 NXP Semiconductors...
Страница 148: ...Analog to Digital Converter S08ADC12V1 MC9S08QL8 MCU Series Reference Manual Rev 1 148 NXP Semiconductors...
Страница 162: ...Internal Clock Source S08ICSV3 MC9S08QL8 MCU Series Reference Manual Rev 0 162 NXP Semiconductors...
Страница 172: ...Modulo Timer S08MTIMV1 MC9S08QL8 MCU Series Reference Manual Rev 1 172 NXP Semiconductors...
Страница 200: ...Serial Communications Interface S08SCIV4 MC9S08QL8 MCU Series Reference Manual Rev 1 200 NXP Semiconductors...
Страница 224: ...Timer Pulse Width Modulator S08TPMV3 MC9S08QL8 MCU Series Reference Manual Rev 1 224 NXP Semiconductors...
Страница 238: ...Development Support MC9S08QL8 MCU Series Reference Manual Rev 1 238 NXP Semiconductors...
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