Freescale Semiconductor Microcontrollers, Manual

Page: 385 / 892

HC08 ICS P&E Multilink/Cyclone Pro Connections
Connection Procedure
385 Microcontrollers Debugger Manual
Tpu and Tpd Timing Textboxes
Tpu and Tpd set the power-up and power-down delay (respectively) that is observed when
power-cycling a target for entry into Monitor Mode. These settings are only valid for
devices with automatically controlled power.
Whenever power is automatically or manually switched off, the software waits for an
amount of time equal to the Tpd delay time before proceeding to the connection protocol.
This is because a board or power supply may have capacitance which holds the power up
for a short time after the supply has been switched off, but the supply voltage must reach
less than 0.1v before it is turned back on if a Power-On reset is to occur.
Whenever power is automatically or manually switched on, the software waits for an
amount of time equal to the Tpu delay time before attempting to contact the M68HC08
processor. This is to allow time not only for power to be fully available, but to allow all
reset drivers to release the RESET line.
Target has RESET Button
In using Class III boards, the software occasionally needs to get control of the target. For a
more detailed description of device classes, see
Device Class Description . On systems
which are Class III boards with the monitor mode circuitry built-in (including RS-232
driver), there is no means to reset the target to gain control. If the board has a reset button,
the software can use this to gain control of the target system. If this option is checked, the
software prompts the user to push the target reset button when a reset of the target system
is desired. If the option is unchecked, the software prompts the user to power cycle the
target system to achieve a reset.
MON08 Cable Connection Communications Type
This selection box is valid only for Class II hardware configurations using the MON08
cable. It allows the user to specify the sequence that the software uses to power up the ICS
system. For a more detailed description of device classes, see
Device Class Description .
When the software tries to create a power-on reset condition, two events must occur:
1. Power of the target MCU must go below 0.1v. This means that the processor cannot be
receiving power from its power pins, nor can it have a significant voltage being driven
on port pins or the IRQ line, as these drive the MCU power back through these pins. It
is crucial, therefore, to have the ICS and the Target both powered down at some point
in time.
2. The processor MON08 configuration pins, including IRQ, must be properly driven
when the target processor resets to drive it into monitor mode. If these pins are not set
up properly before the processor powers up, the processor may start up in user mode.