82c55 PIA replacement?
Bellows
We are proto-ing up a board for the lab for some data acquisition needs
we have, an 8051 core for primarily data i/o and storage (with a few
odds and ends added in). I need to expand the bus a bit for some
peripherals, and anticipated using the ol' 8255, but it has been
dropped by Intel (in all its versions). (Surplus market still has 'em,
but I need this design to have a bit longer shelf life.)
So, any suggestions for a PIA or bus extender for a small embedded
engine? All suggestions would be most welcome!
TIA,
Tom Bellows
Paul Dougherty
> I need to expand the bus a bit for some
>peripherals, and anticipated using the ol' 8255, but it has been
>dropped by Intel (in all its versions). (Surplus market still has 'em,
>but I need this design to have a bit longer shelf life.)
>
>So, any suggestions for a PIA or bus extender for a small embedded
>engine? All suggestions would be most welcome!
In no particular order...
1. Use another maker of 8255. :)
2. Add a PIC16C65 which has a parallel "slave port" like the 8041 or Intel
80C452.
(The 2nd processor could be a benefit or a curse.)
3. Use a bigger '51 like a Philips 80C451 (68 pins).
4. Use a PLD or CPLD.
--Paul
Cass
8255 but, it is cumbersome to use, takes up lots of real estate for
only two ports and is much harder to write software for than the
'244s.
Cass
Paul Dougherty <pa...@europa.com> wrote in message
news:37d9...@news.nwlink.com...
G.S. Vigneault
programmable modes of the 8255 -- which can be changed on-
the-fly, for very flexible interfacing options.
There are numerous alternate sources for the 8255, which has
many more years of life.
(BTW, the 8255 has three ports, not two.)
Greg_
http://home.korax.net/~telic
September 11, 1999, Toronto.
Paul Bealing
Cass <casseg...@galaxycorp.com> wrote in message
news:7rcofe$qsj$0...@dosa.alt.net...
> The 8255 is a real Dinosaur; use '244s, instead. I used to use the
> 8255 but, it is cumbersome to use, takes up lots of real estate for
> only two ports and is much harder to write software for than the
> '244s.
There is a PLCC pack but it may be hard to get, I don't know.
I have an older design using one 82C55 and two 244s (534s actually). The 244
cannot be read back without extra hardware, making bit operations more
difficult. The biggest 82C55 disadvantage is that for a big chip you cannot
individually set port bits as input or output. The best you can do is split
port C, 4 in and 4 out. IMO, writing the software for an 82C55 for byte
operations couldn't be much easier.
The best solution will depend on the expansion required; is bit manipulatin
required? is it bi-directional?
Based on recent investigations I'd recomment CPLD, and put other stuff in
there as well (glue logic etc). I'm looking at the Altera 10K series at the
moment, there is a big learning curve.
Regards
--
Paul Bealing
www.pmb.co.nz
Zefram Cochrane
: odds and ends added in). I need to expand the bus a bit for some
: peripherals, and anticipated using the ol' 8255, but it has been
: dropped by Intel (in all its versions). (Surplus market still has 'em,
As far as I am aware, OKI still do it, in the 28-pin PLCC version.
Richard [in CM8]
Robert Gush
bel...@ucrac1.ucr.edu wrote:
> Hello everyone,
>
> We are proto-ing up a board for the lab for some data acquisition
needs
> we have, an 8051 core for primarily data i/o and storage (with a few
> peripherals, and anticipated using the ol' 8255, but it has been
> dropped by Intel (in all its versions). (Surplus market still has 'em,
>
> So, any suggestions for a PIA or bus extender for a small embedded
> engine? All suggestions would be most welcome!
>
> Tom Bellows
>
>
If you want to do bit I/O then a use 74xx259 for output or 74xx251
for input. Only needs 1 databit.
--
Regards - Robert
Sent via Deja.com http://www.deja.com/
Share what you know. Learn what you don't.
G.S. Vigneault
Take a look at the bus-expansion chips from Waferscale
(www.waferscale.com). These effectively recover the 8051
i/o ports or address bus. They also have Flash memory solutions
for the 8051 and 68HC11 families.
Greg Vigneault
http://home.korax.net/~telic
September 11, 1999, Toronto.
>In article <37D9675D...@ucrac1.ucr.edu>,
Mark
was able to reduce the part count by 10 chips! It has a PLD, Tons of Flash
(two separate sections for running from and programming the other), a bunch
of RAM, and EEPOM. All this with a JTAG port and a battery standby input.
They are also very easy to use, and are very flexible. They are under $10 in
quantity.
e-mail me if you want any more information.
-Mark Wyman
"G.S. Vigneault" <telic@netscape_DOT_net> wrote in message
news:37dab81b....@news.korax.net...
Richard Erlacher
FPGA or CPLD.
However, with the 82C55 you still have to buffer the signals if you
intend to drive any sort of load at all, so I would look for a
specific configuration you want to address and build it in a
programmable device with sufficient output current to meet your needs.
You can, of course, build it in family logic as some have suggested,
though I'd carefully look at the requirements before doing it in the
somewhat obtuse ways which have been recommended. A small CPLD in a
PLCC-44 should not only replace the 82C55 but provide sufficient
output current for you as well. The advantage, of course, is that you
can skip the software setup, since the configuration is controllec by
your jedec file.
Dick
On Fri, 10 Sep 1999 13:17:33 -0700, Bellows <bel...@ucrac1.ucr.edu>
Ian McNeill
>The 8255 is a real Dinosaur; use '244s, instead. I used to use the
>8255 but, it is cumbersome to use, takes up lots of real estate for
>only two ports and is much harder to write software for than the
>'244s.
Ummm 8255 has 3 ports, not 2, one of which can be bi-direction. Also
the major difference between it and just using a 244 is that the current
state of the o/p ports can be read back from the chip.
--
Regards---Ian.
May the road rise up to meet you, Email to:
May the wind be at your back, imcn...@mccomp.demon.co.uk
May the sun always warm the side of you face,
and may God always keep you in the palm of his hand
Zefram Cochrane
> As far as I am aware, OKI still do it, in the 28-pin PLCC version.
Sorry, I meant 44-pin PLC. I was thinking of the 8251 USART, with which
we are having similar supply ambiguities.
: Richard [in CM8]
Spehro Pefhany
> dropped by Intel (in all its versions). (Surplus market still has 'em,
> but I need this design to have a bit longer shelf life.)
I think it will continue to be supplied (the CMOS version) by other
suppliers for quite some time. That's just an opinion though.
Unfortunately, I can't think of a better alternative.
Have you considered networking another micro to the first one through an
I2C or SPI bus?
--
=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=
Spehro Pefhany "The Journey is the reward"
sp...@interlog.com
Fax:(905) 271-9838 (small micro system devt hw/sw + mfg)
=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=
Robert Gush
Spehro Pefhany <sp...@interlog.com> wrote:
> the renowned Bellows <bel...@ucrac1.ucr.edu> wrote:
> > dropped by Intel (in all its versions). (Surplus market still
has 'em,
> > but I need this design to have a bit longer shelf life.)
>
> I think it will continue to be supplied (the CMOS version) by other
> suppliers for quite some time. That's just an opinion though.
> Unfortunately, I can't think of a better alternative.
>
We found the CMOS part VERY susceptable to SCR latchup. Almost
any other solution would be better.
Paul Bealing
common for one of them to be reset without the micro being reset, they are
all tied together. The result was that the outputs became inputs.
Unfortunately the micro code did not anticipate or correct the problem,
involving a technician going out and push the reset button.
The micro is convinced that the outputs are working, but nothing.
Basically just a problem with the code, bad house-keeping.
Regards
--
Paul Bealing
www.pmb.co.nz
Robert Gush <sues...@suesound.co.za> wrote in message
news:7rh5oq$d22$1...@nnrp1.deja.com...
Anton Erasmus
bit port. It has 3 x 16 bit timers as well. The Ports are very
flexible. Each bit can be programmed for Input or Output. They can be
programmed for Totem-Pole or Open-Drain output. A port pin can
generate and interrupt. etc. Zilog has a PDF version of the data sheet
on their Web site.
Regards
Anton Erasmus
On Fri, 10 Sep 1999 13:17:33 -0700, Bellows <bel...@ucrac1.ucr.edu>
wrote:
>Hello everyone,
>
>We are proto-ing up a board for the lab for some data acquisition needs
>we have, an 8051 core for primarily data i/o and storage (with a few
>odds and ends added in). I need to expand the bus a bit for some
>peripherals, and anticipated using the ol' 8255, but it has been
>dropped by Intel (in all its versions). (Surplus market still has 'em,
>but I need this design to have a bit longer shelf life.)
>
Bellows
Thanks to all for the excellent suggestions. I was able to track down
another source, so may go with the 8255 for the moment (Harris/Intersil web
sites list 'em, but distrubutors can't find 'em listed, Fairchild doesn't
do 'em, TI is out of the loop,/Dallas, /Maxim, /Motorola, one Oki
distributor found a few, etc.). The ideas about the waferscale chips are
indeed interesting, and I will be following those up. Using buffers and
latchs ('244, '245) gets a bit cumbersome in this application, as each part
of the extended bus needs to be programmably bidirectional, which would
take a few extra chips. And rolling my own.....best idea yet, I suspect,
oh for the time to be sensible and efficient!
In all, a very helpful set of suggestions. Thanks again to everyone who
replied!
Regards,
Bellows
alsa...@my-deja.com
converters. 4 pins expand to 32 pins, 5 pins
expand to 64 pins, and so on, 32pins/extra pin.
Sobby Jose
> We are proto-ing up a board for the lab for some data acquisition needs
> we have, an 8051 core for primarily data i/o and storage (with a few
> odds and ends added in). I need to expand the bus a bit for some
> peripherals, and anticipated using the ol' 8255, but it has been
> dropped by Intel (in all its versions). (Surplus market still has 'em,
> but I need this design to have a bit longer shelf life.)
>
> So, any suggestions for a PIA or bus extender for a small embedded
> engine? All suggestions would be most welcome!
Check WSI. They are mfg: devices which has Built in ROM as well as RAM
with I/O Ports. The advantage U have while using WSI is that the glue
logic for external memory is eliminated.
Thanks
Sobby Jose
Ashok Mahadevan
since I was unable to come with anything like this on the Zilog website.
Thanks,
Ashok
G.S. Vigneault
Greg_
http://home.korax.net/~telic
September 17, 1999, Toronto.
On Fri, 17 Sep 1999 14:26:34 +0530, Sobby Jose <so...@HotPoP.com>
wrote:
Steven K. Knapp
System-on-Chip (CSoC) devices.
These contain an 8051-compatible 8032 "Turbo" microcontroller, which is
similar to the Dallas 80C320. It operates about 2.5x faster than the
original 8051 at the same clock frequency. These also operate up to 40 MHz.
It also contains the standard 8052 peripheral set, plus a two channel DMA
controller, and integrated debugging support.
Internally, the devices have a large block of programmable logic for
creating your custom logic functions. The related development software even
has "soft" modules for popular microcontroller functions such as SIP
interface, additional UARTs, etc. The smallest device offers about 5,000
programmable gates while the largest is about 40,000 gates.
Also, there's a large block of on-chip SRAM, again ranging from 16K bytes on
the smallest device to 64K bytes on the largest.
Connecting the processor, memory, and logic together is a extendible
high-performance bus. The bus distributes address, data, control, address
decoding, wait-state control, DMA control, and breakpoint control to and
from the programmable logic. You can even extend the bus off-chip to other
devices.
If you're interested, I'd recommend visiting the Triscend web site at
http://www.triscend.com and especially the Online Learning Center at
http://www.triscend.com/learning.
--
Steven K. Knapp
Triscend Corporation
301 N. Whisman Rd.
Mountain View, CA 94043 USA
Tel: 650-968-8668 x-166, FAX: 650-934-9393
skn...@triscend.com, Web: www.triscend.com
> On Fri, 10 Sep 1999 13:17:33 -0700, Bellows <bel...@ucrac1.ucr.edu>
> wrote:
>
> >Hello everyone,
> >
> >We are proto-ing up a board for the lab for some data acquisition needs
> >we have, an 8051 core for primarily data i/o and storage (with a few
> >odds and ends added in). I need to expand the bus a bit for some
> >peripherals, and anticipated using the ol' 8255, but it has been
> >dropped by Intel (in all its versions). (Surplus market still has 'em,
> >but I need this design to have a bit longer shelf life.)
> >
> >So, any suggestions for a PIA or bus extender for a small embedded
> >engine? All suggestions would be most welcome!
> >
> >TIA,
> > Tom Bellows
> >
>
Olav Woelfelschneider
SKK> Another option that may interest you are the new Triscend E5 Configurable
SKK> System-on-Chip (CSoC) devices.
Sounds expensive. Do you have some example numbers for us?
--
Olav "Mac" Wölfelschneider wo...@cardware.de
PGP fingerprint = 06 5F 66 B3 2A AD 7D 2D B7 19 67 3C 95 A7 9D AF
We are but packets in the internet of life. (Illiad)
Steven K. Knapp
Olav Woelfelschneider <wo...@cardware.de> wrote in message
news:489vr7...@hex.athome.de...
Sorry, I should have included some example pricing. Here are today's
100-piece price through U.S.-based distributors. Like most semiconductor
prices, the prices are lower for volume purchases and prices drop over time
as production volumes ramp. If you contact a Triscend sales representative,
he or she can provide you with a quote specific to your production volume
requirements and time-frame. See
(http://www.triscend.com/salessupport/IndexSalesContact.html).
EXAMPLE PRICING FOR TRISCEND E5 CONFIGURABLE SYSTEM-ON-CHIP (CSOC)
---------------------------------------------------------------------------
Part Number: TE505S16-25LC
Features:
* 8051/52-compatible "Turbo" microcontroller
- Three timer/counters
- UART
- Watchdog Timer
- Interrupt Controller
- 256 bytes of processor RAM (DATA)
- Dual data pointers
- About 2.5x to 3x faster than original 8052 microcontroller
operating at the same clock frequency
* Two channel DMA controller
* JTAG/hardware breakpoint unit
* Internal high-speed bus, including wait-state control
* 16K bytes of internal system RAM (XDATA)
* 512 programmable logic cells (about 5,000 programmable gates)
* 32 programmable address decoders
* 60 user-programmable I/O pins (up to 84 in certain modes)
* 25 MHz bus speed (programmable logic operates up to 100 MHz)
* 128-pin thin PQFP package
* Commercial temperature range (0C to +70C)
100 Unit Price: US$13.55
[on a side note, the press release stated a high-volume price below US$8.]
---------------------------------------------------------------------------
Part Number: TE505S16-25QC
Features:
(same as above with the following exceptions)
* 100 user-programmable I/O pins (up to 124 in certain modes)
* 208-pin PQFP package
100 Unit Price: US$17.45
---------------------------------------------------------------------------
Part Number: TE520S40-25QC
Features:
(same as above with the following exceptions)
* 40K bytes of internal system RAM (XDATA)
* 2,048 programmable logic cells (about 25K to 30K programmable gates)
* 128 programmable address decoders
* 126 user-programmable I/O pins (up to 150 in certain modes)
* 208-pin PQFP package
100 Unit Price: US$45.00
---------------------------------------------------------------------------
On the software side, the Triscend FastChip Configurable System-on-Chip
Development System (TDS-BAS-LIC) sells for US$495.00. The Triscend Starter
Kit (THW-KIT-520), including both development software and the Triscend
Development Board, sells for $1,395.00.
Number Cruncher
They have an improved high speed 8255 under a slightly changed name ->
(contact: Arrow)
regards,
Michel
Bellows <bel...@ucrac1.ucr.edu> wrote in message
news:37DEE572...@ucrac1.ucr.edu...
Don McKenzie
>
> Did you consider NEC ...
> They have an improved high speed 8255 under a slightly changed name ->
> (contact: Arrow)
>
> regards,
>
> Michel
I have about 160
http://www.dontronics.com/specials.html
Don McKenzie mailto:d...@dontronics.com http://www.dontronics.com
Don's Download Dungeon: http://www.dontronics.com/download.html
Australian Electronics Ring http://www.dontronics.com/aering.html
Win $500USD Cash. Micro design contest: http://www.simmstick.com