HMC7000 Series I/O Module Guide
9
HMC7000 Series I/O Module Guide
9
Reference the table below when configuring each HSC Configuration Register (MWnn00 and MWnn06):
Bits
Function
15-4
Not used
3
0 : Falling Edge
1 : Rising Edge
2, 1, 0
Module Operating Mode :
000 : Normal Operation
010 : Up Counter HSC
To implement High Speed Counter Operation:
1.
Connect a device to X0 (Channel 1) or X5 (Channel 2) that will provide the high speed pulses to the
expansion module.
2.
Configure the HSC using the configuration register MWnn00 (Channel 1) or MWnn06 (Channel 2).
3.
Write the HSC preset count value in MWnn03 (Channel 1) or MWnn09 (Channel 2).
4.
Enable the HSC by setting the HSC Enable Bit Mnn080 (Channel 1) or Mnn176 (Channel 2).
5.
HSC increments (starting from 0) the current value register in MWnn01 (Channel 1) or MWnn07
(Channel 2) until the preset value is reached.
6.
Enable the HSC Reset Bit by setting Mnn081 (Channel 1) or Mnn177 (Channel 2). This will cause the HSC
current value to reset back to 0.
7.
To start the process again, simply reset (clear) the HSC Reset Bit and set the HSC Enable Bit. Note: if the
HSC Enable Bit is still ON, you must reset (clear) this bit, and then set it again.