8052.com page
My personal area on 8052.com
Just had to put a placeholder here to see how the new
homepage process works. I'm currently writing up some notes on an 8032 based
card (with RAM, RTC & EPROM) which could be purchased for £2 from
a UK based surplus supplier. Will share the details here so that anyone else
who wants to get up to speed on the 8052 can have a cheap & cheerful start.
Before we go any further, you should note that this card uses
an EPROM to hold your 8032 code - if you don't have an EPROM programmer/eraser,
this card won't be of very much use to you.
That said, it does have :
an 8032 based CPU
a battery backed up static RAM chip 76C2656 (32KBytes)
a socketed 27512 EPROM (64Kbytes)
a battery backed up Real Time Clock
a small buzzer device
a backup battery
two edge connectors which are wired to some of the CPU I/O pins
|
Top view (click for a better image)
|
Bottom view
|
To get started, you will need a regulated 5VDC power supply.
The card has no on-board regulation. Since there is a battery on the board,
a regulated supply is important - the current which the board draws
may change over time as the battery charges up.
Connectors
There are 2 main connectors on the card. One is 11 way, the
other is 16 way. Fortunately, some of the 8032 I/O pins run directly to these
connectors.
11 way connector beside CPU
O0 - P1.0
O1 - P1.1
O2 - P1.2
O3 - P1.3
O4 - P1.4
O5 - P1.5
I0 - Pin17 on the 74HCT244
I1 - Pin15 on the 74HCT244
I2 - Pin13 on the 74HCT244
I3 - Pin11 on the 74HCT244
I4 - Pin 8 on the 74HCT244
16 way connector J1
1 - 0v
2 - +5v DC
3 - wiper of blue 10k preset
4 - pin 5 on the RTC (A1)
5 - pin 2 on the 74HCT373
6 - pin 15 on the pal
7 - pin 14 on the RTC (D0)
8 - pin 13 on the RTC (D1)
9 - pin 12 on the RTC (D2)
10 - pin 11 on the RTC (D3)
11 - pin 12 on the 74HCT244
12 - pin 14 on the 74HCT244
13 - pin 16 on the 74HCT244
14 - pin 19 on the 76C2656 RAM
15 - +5v DC
16 - 0v
SRAM
The static RAM is memory mapped from $0 to $7FFF in the data
space. Remember that the 8032 has separate program and data address spaces
(the 8032 accesses the SRAM with the 'movx' instruction).
Real Time Clock Info
The OKI M6242B RTC device is memory mapped to $C000 in the data
space. I have the data sheet for this device as a .pdf file.
Battery
The 3.6V 100mA Varta 'mempac' battery is fitted to the rear
of the card. As the cards are quite old, the batteries may not be in very
good condition. Hint - when you get your card, remove jumper 'SW1' this will
stop the battery from draining any further. Refit the jumper when you want
to charge the battery.
Caveat
Bear in mind that this card is from a surplus supplier. There
is no guarantee that it will work at all (however, I've purchased quite a
few & they all worked). Also, once the supplier runs out of stock you
won't be able to get any more, so don't rely on being able to get a spare!
The folk who sold this card are UK based Greenweld
Electronics. Sadly, now all sold out.
A smart guy (Eric Chung) took the time to draw an ORCAD schematic
of this board. Let me know if you would like a copy.
Do drop me a note if you bought one of these & did anything
interesting with it.
Derek Kennedy (minerva9@hotmail.com)
Created: 1st June 2001
Last Updated: 24th June 2002
