[f-cpu] New VHDL Stuff

[Michael Riepe <michael@stud.uni-hannover.de>]

Hi F-gang!

I'm going to upload my latest sources to seul.org tonight; look for
http://f-cpu.seul.org/~f-cpu/new/fcpu-mr-20030327.tar.gz.

As I already mentioned, there are new INC and CMP units.  I also improved
the adders in EU_ASU and EU_IMU, and added new functions to the ASU and
SHL units (see the list of changes below).

While playing with the multiplier again, I noticed that it may be possible
to integrate a `scalar product' function without increasing the latency
of the unit.  That function would multiply its operands in SIMD mode,
delivering double-width temporary results, and then add all the temporary
results and produce a 128-bit sum, with only minimal hardware overhead.
The latency will be 6 cycles regardless of the chunk size, with chunk
sizes of 8...64 bits supported (in 64-bit mode, the function is identical
to `mulh').  I don't know if it will support signed multiplications,
but I guess it should be possible.  Does that sound useful?  I believe
it may be an alternative to mac/amac in some cases.

Changes:

	* eu_asu/iadd.vhdl:
		- auto-sizing unit (WIDTH must be a multiple of 64)
		- new increment-and-add and average operations
		- improved adder stages

	* eu_asu/iatest7.vhdl:
		- new (faster) testbench for iadd.vhdl

	* eu_imu/imul64.vhdl:
		- improved adder stages
		- 8/16/32/64 bit timing is now 3/4/5/6 cycles for both outputs

	* eu_imu/im64test4.vhdl:
		- additional testbench for imul64.vhdl

	* eu_imu/im64testconf.vhdl:
		- configuration file for IMU testbenches

	* eu_shl/shuffle64.vhdl:
		- fixed bitrev operation
		- added permute and cshift functions

	* eu_cmp/*:
		- new integer compare unit (handles cmp/min/max/msb0/msb1)
		- auto-sizing unit (WIDTH must be a multiple of 64)

	* eu_inc/*:
		- new integer increment unit (handles inc/dec/neg/abs/lsb0/lsb1)
		- auto-sizing unit (WIDTH must be a multiple of 64)

-- 
 Michael "Tired" Riepe <Michael.Riepe@stud.uni-hannover.de>
 "All I wanna do is have a little fun before I die"
*************************************************************
To unsubscribe, send an e-mail to majordomo@seul.org with
unsubscribe f-cpu       in the body. http://f-cpu.seul.org/