mesa driving shift registers

Hello.
These I/O modules www.se.com/us/en/product/170ADM35010/dis...-16-i-o-solid-state/
inside have HC165 (input shift registers) and HC595 (output shift registers)
No mcu - no proprietary communication protocol just simple shift registers.
The driving of these shift registers is done by black connector with 12 pins (8 pins is the driving signals of shift registers and other 4 are 5v supply).
Can hostmot2 modified to drive this I/O modules like sserial module?
Can this be done only in hostmot2 firmware or also needs linuxcnc hostmot2 driver modification?

Other option  is to use an mcu or a cpld with sserial to communicate with mesa like sserial card.
Can  i found somewhere mesa sserial specification ?
 

The smart serial spec can be found in the 7i73 manual starting on page 25.

I've attached the code that runs on the 7i90 in smart serial mode. The code is for one of the soft-cores that run on the fpga. The instructions aren't that hard to work out. It should give you an idea of how it works, shouldn't be that hard to port to another mcu.

I modified the code to use a colorlight rv901t as a sserial device to add extra MPG inputs.

It could also be done by bit-banging. There's example of using shift registers with Parallel Port on the wiki.
wiki.linuxcnc.org/cgi-bin/wiki.pl?Shift_Register_Port_Expander

Mesa also has smart serial IO cards
store.mesanet.com/index.php?route=produc...oduct&product_id=113

Yes, these could be driven but it would require 2 new HM2 firmware modules
and a new driver (or 2 new) drivers. None of those are very complicated.
Do the modules loop back the shift register output data? That would be nice
for auto sizing and presence detection.