September 29.
OK. Lets get to work.
First I make the schematics and adapt it to fit to the TBL28L22.
This means to examine what i s needed for programming theese properly.
It turns out that the TBL28L22 need quite a few voltages in various places at various times to be programmed safely.
So let's look at the timing chart.
Ther is of course, a +5V. This one should raise to +6V during programming.
There is a +10V for the program enable on the TBL.
There is a +16V for burning those fusible links in the TBL during programming. And they are all to occour at spesific intervals and rise-time.
To keep the powersupply simple, but effective I bulid a combination of fixed linear regulators ans switches the voltages using transistors.
The +16V is spesified to have a certain slope, with a risetime of about 15uSecond. This is achieved wth a simple RC-filter in the supply of the base voltage on the output transistor for the 16V.
The other voltages are just to change status as fast as possible, prefereably within a uSecond. Simple transistorswitches is suitable to obtain this.
I have chosen to build this programmer based on an ARDUNIO ONE.
Forst og all, 'cause I have some lying around, and next because I so easily can obtain the number of IOs for this project as I require.
For the ease of the build, aswell as for the quite reasonable price of it, I use a DIO 24-ARD to get 3 times 8bit IO. It's qiute simple to use with the ARDUNIO ONE, as it simply is plugged on top of the ARDUNIO, Choose a single bit from the ARDUNIOS IOs, connects the MISO and MOSI along with the I2Cbus.
Some simple codes to adapt it all and there it is.
A couple 74S374 is used in the same matter as Agp.Coopers design, as is the transistorswitches for the programming and veryfying of the program.
At this pint I have no program yet, as I will have to enter the code for the TBL manually. I have no chips there is any program to download.
I will look in to it with my software-friend, as I have no idea whatsoever to design the program needed for this programmer.
This will take some time, and for those who have tips and recomondations, I would be very happy to see Your comments here.
The schematics will be bompleted with spesifications as soon as possible.
TANDBERGEREN
Update Oct. 4.
Got a message from my supplier of the DIO-24 ARD:
"We will not be able so supply theese boards until late November "
Boomer.
Well, I will have some time to tweak the basic design then.