External Sram

solarprism · 2010-12-15 18:09

In AVR i know that there is a register that if we set it,AVR will automatically use external sram as it own ram.Is there something similar to that in Prop.I searched the manual but havenot seen it :blank:

Mike Green · 2010-12-15 19:29

No, there is no way to use external memory as a direct extension of the internal RAM/ROM. That's why you can't find anything in the manual. There are various I/O drivers that let you use external memory, but it's a kind of 2nd level storage. Several of the emulators, like the Z80 emulator and the ZOG emulator, can use external SRAM and the Catalina C compiler can generate code that executes in a semi-interpreted fashion out of external SRAM. All of these have a time penalty for this, but it's pretty reasonable.

The Prop II is supposed to have several features that will make the use of external memory more efficient, but it still won't be treated as the same as its internal memory.

Ravenkallen · 2010-12-15 19:34

There is no way to incorporate external ram directly with a Propeller program. The IDE only supports programs that are 32K or smaller, plus the Prop has no means of address external memory as if it was its own SRAM. Others have used external ram, but only by turning the Prop into a interpreter... You could look at some of the other Prop programming languages out there and see if you could use something like that.

Whoops, looks like Mike beat me to it

solarprism · 2010-12-16 20:19

i want to read a bmp image file from SDcard and display to VGA monitor,can you suggest me a solution

Mike Green · 2010-12-16 20:39

You probably want to read a large bmp image file from an SD card, one too large to fit in 32K of hub memory.

Have a look at the Morpheus board from Bill Henning. This is a dual Propeller board with external SRAM on one of the Propellers. Bill has gone to the trouble of writing VGA drivers that use the SRAM as a bitmap buffer for the display so you can have a larger bitmap than can fit in 32K.

Dr_Acula · 2010-12-16 20:45

If you want to read a bitmap off sd card and display on a vga monitor you may not need external ram. These videos were done using a vga on pins 16-23 and an sd card on 12-15. The board does have an external ram but it is not used for either of these videos. Board is a Dracblade http://www.smarthome.viviti.com/propeller

If you have a demo board all you really need is an sd socket and some 10k resistors.

http://www.youtube.com/watch?v=170HLfl6VfI and http://www.youtube.com/watch?v=0NTXOG_HfVY

solarprism · 2010-12-17 17:30

Dr_Acula wrote: »

If you want to read a bitmap off sd card and display on a vga monitor you may not need external ram. These videos were done using a vga on pins 16-23 and an sd card on 12-15. The board does have an external ram but it is not used for either of these videos. Board is a Dracblade http://www.smarthome.viviti.com/propeller

If you have a demo board all you really need is an sd socket and some 10k resistors.

http://www.youtube.com/watch?v=170HLfl6VfI and http://www.youtube.com/watch?v=0NTXOG_HfVY

Thank you all

especially Dr_Acula
If anyone travel to Hanoi,notice me,i guide you through the town

Oldbitcollector (Jeff) · 2010-12-17 22:38

Dr_Acula wrote: »

If you have a demo board all you really need is an sd socket and some 10k resistors.

http://www.youtube.com/watch?v=170HLfl6VfI and http://www.youtube.com/watch?v=0NTXOG_HfVY

DrA, Would you share how you did the TAZ video? That framerate looks pretty quick for VGA being read from SD.

OBC

Dr_Acula · 2010-12-18 16:30

Hi OBC,

Yes I must write that up. It only is one line of Spin that glues together Kye's video driver and Kye's sd card routines. So any credit for the speed needs to go to Kye. Preliminary writeup here http://forums.parallax.com/showthread.php?127448-Play-movies-on-the-propeller&highlight=movies

Maybe these sorts of things now belong on the Blogs instead of the Forum??

By an amazing coincidence the speed ended up just right for a movie. If it had turned out too fast I was going to put in delays. If too slow, I would not have published it!

There is also some other code - you need to capture a youtube video and run a vb.net program to take each frame, scale it, reduce the colors to 64 and create all the bitmap files. Then turn all those into a single binary file. I automated most of that, but you will need vb.net 2008 to run it.

@ solarprism, I also have some vb.net code to create static pictures. I was doing these in Paintshop Pro, but it got very tedious. Once you get the sd card connected and working I can help you with that code.

solarprism · 2010-12-20 01:40

Dr_Acula wrote: »

Hi OBC,

Yes I must write that up. It only is one line of Spin that glues together Kye's video driver and Kye's sd card routines. So any credit for the speed needs to go to Kye. Preliminary writeup here http://forums.parallax.com/showthread.php?127448-Play-movies-on-the-propeller&highlight=movies

Maybe these sorts of things now belong on the Blogs instead of the Forum??

By an amazing coincidence the speed ended up just right for a movie. If it had turned out too fast I was going to put in delays. If too slow, I would not have published it!

There is also some other code - you need to capture a youtube video and run a vb.net program to take each frame, scale it, reduce the colors to 64 and create all the bitmap files. Then turn all those into a single binary file. I automated most of that, but you will need vb.net 2008 to run it.

@ solarprism, I also have some vb.net code to create static pictures. I was doing these in Paintshop Pro, but it got very tedious. Once you get the sd card connected and working I can help you with that code.

thank you DrA,i will start working right after i finished my exam

External Sram

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