In SX Microcontrollers, SX/B Compiler and SX-Key Tool, peterverkaik wrote:

The VP libraries are updated. I added pinSetup for the vpInstall() function
so all elements for dynamic VP loading are in place.
Had to redefine the PORTPIN values to make the code more compact.

To prevent possible glitches on I/O pins when port direction registers
are updated from both mainlevel code and interrupt code, I declared
DDR copy registers in bank 0xF0. This also has the benefit that SX28
code can read the direction registers (actually the copies), but more
importantly, it offers an easy way to prevent glitches.

The sequence to write to the DDR registers, once M is set, is:
MOV W,DDRACOPY ;any DDR copy register
MOV !RA,W

If an interrupt occurs inbetween those 2 instructions, and the interrupt
would update direction bits for port RA, then the interrupt update becomes
undone.
The function DDRupdate in library Portpin.h inserts an extra clockcycle
when an RTCC rollover would occur inbetween those 2 instructions.
As a result, the interrupt occurs before the MOV W,DDRACOPY instruction,
so if the interrupt update the DDR registers, the change is maintained.

Library Portpin.h contains a large number of small routines to make pins inputs
or outputs, low or high and also a large number of small routines that operate
on ports.

The VP uarts have been updated and now include code for handshaking.
With the port and pin functions available I can start to make a real demo
program that actually runs.
The attached vp_test.c compiles without error so you can checkout the
generated code.

In a couple of days I should have a working demo that demonstrates the
loading and unloading of virtual peripherals.
Unzip libraries.zip to the CC1B folder. Place vp_test.c into the C4SX folder.

regards peter

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