gnupic: gpsim CVS update
Subject:
gpsim CVS update
From:
Scott Dattalo ####@####.####
Date:
15 Mar 2000 13:52:05 -0000
Message-Id: <Pine.LNX.4.21.0003150711370.4589-100000@tempest2.blackhat.net>
FYI,
After taking a week off from gpsim, I jumped back in and added support for USART
in the 14-bit core. It's not fully functional, but here's what's supported:
asynchronous transfers
9-bit mode
Interrupt on rx and tx
mapping to I/O pins
Right now, only the 40-pin versions of the 14-bit core devices have the
uart. This includes the 16c65 (not the c64 - it doesn't support the uart in the
real device), 16c74, 16f874, and 16f877.
As a simple test, I wrote a routine called usart_14.asm (in cvs
examples/14bit) that reads and writes to and from the uart. If you create a node
that loops tx back to rx, you can actually receive the bytes that are
transmitted - just like a real rs-232 loop back!
There were some fixes to the 10-bit a/d converter in the 16f877 as well. Now,
the ADFM bit properly selects the format (the way the 10-bit value is mapped
into two 8-bit registers). In addition, the analog scaling works properly
now. Consequently, analog stimuli (which are expressed in terms of voltages) are
scaled such that if the A/D converter is 8 or 10 bits the digital value is
correct.
I had to make some significant changes to the stimulus infrastructure too.
Partially because it has become somewhat broken due to neglect and partially
because the analog portion was just plain broken.
Ralf has just started the program memory browser that will you to modify the
program memory much in the same way you can modify the register memory.
Scott
