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4.7 Other I/O
4.7.1 Emulator connection
An 11-pin footprint on the rear of the card marked 'ICE' provides access to the processor for
boundary scan emulation. To connect the Texas Instruments emulator pod, a two row 12-pin
0.1in pitch surface mount pin header with pin 8 missing must be fitted. The connections are
those specified by Texas Instruments. See the 'MintMT Embedded Programming Guide' for
details on emulator based system debugging.
4.8 Reset states
During power up, NextMove PCI is held in a safe non-operational state known as hardware
reset. It will also go into hardware reset if the 5V supply drops below approximately 4.75V, to
prevent uncontrolled operation due to the electronics losing power. When NextMove PCI is in
hardware reset for any reason, most of the controlled interfaces fall into known states. It is
also possible for NextMove PCI to be in a state known as software reset. This is a safe
operational state where only the bootloader firmware present on NextMove PCI is running.
Hardware and software reset states should not be confused with the Mint keyword RESET
which is used to clear axis errors.
Communications
At power up the CAN controllers will be held in reset and will have no effect on the CAN
buses. If a reset occurs during the transmission of a message CAN errors are likely to occur.
Dual Port RAM (DPR) will contain no information at power up but will be accessible by the PC.
A reset during operation will cause the DPR to stay in its current state.
Digital Outputs
All of the digital outputs are inactive on power up regardless of their polarity. They will return
to the inactive state whenever a reset occurs.
Analog Outputs
All analog outputs are set to 0V by hardware during power-up and will return to 0V on a reset.
Stepper/Encoder ASICs
The stepper/encoder ASICs will not generate stepper pulses or register any encoder input
during reset. If the unit goes into reset all position data will be lost.
4.8.1 System watchdog
The system watchdog provides hardware protection in the event of a firmware or embedded
'C' program malfunction. If the system watchdog is not updated, the controller is put into the
software reset state. It may be disabled during embedded code development and debugging.
MN1903
Input / Output 4-23
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