Input/ Output 4-23MN1903

4.7 Other I/O

4.7.1 Emulator connection

An11-pin footprint on the rear of the c ard marked ‘ICE’ provides access to the proc essor for
boundarys can emulation. Toconnect the TexasInst ruments emulator pod, a two row 12-pin
0.1inpitch s urface mount pin header with pin 8 missing must be fitted. Theconnec tions are
thoses pecified by Texas Instruments. Seethe ‘MintMT Embedded Programming Guide’ for
detailson emulatorbased systemdebugging.
4.8 Reset states
Duringpow er up, NextMove PCI is held in a safe non-operational state k nown as hardware
reset. Itwill also go into hardware reset if the 5V supply drops below approximately4.75V, to
preventunc ontrolled operation due to the electronics losing power. When NextMove PCI isin
hardwarer eset for any reason, most of the controlled interfaces fall into known s tates. It is
alsopos sible for NextMove PCI to be in a state known as s oftware reset. Thisis a safe
operationals tate where only the bootloader firmware present on NextMove PCI isrunning.
Hardware and software reset states should not be confused w ith the Mint keyword RESET
whichisusedtoclearaxiserrors.
Communications
Atpower up t he CAN controllers will be held in reset and will have no effect on the CAN
buses. Ifa reset occurs during the transmiss ion of a message CAN errors are likely to occ ur.
DualPort RAM(DPR) will contain no information at power up but will be acc essible by the PC.
Ares et during operation will cause the DPR to stay in its c urrent state.
DigitalOutputs
Allof the digital outputs areinactive on power up regardless of their polarity. Theyw ill return
tothe inact ive state whenever a reset occurs.
AnalogOutputs
Allanalog outputs areset to 0V by hardware during power-up and will return to 0V on a res et.
Stepper/EncoderASICs
Thestepper /encoder ASICs will not generate stepper pulses or register any encoder input
duringres et. If the unit goes into reset all position data will be lost.

4.8.1 Systemwatchdog

Thesystem watchdog provides hardware protection in the event of a firmw are or embedded
‘C’program malfunction.Ifthe system watchdog is not updated, the controller is put into the
software reset state. It may be disabled during embedded code development and debugging.