Looking for Info

Kye

Hello,
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I'm working a new project to make a·couple of propeller chips work as multi-functionally standalone unit that can be programmed without the use of a programming language (yeah, sounds crazy). I'm still just starting on it though and there are most likely years of more work to-do but I have time.
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However,·I need some help locating resources to figure out how to write a keyboard driver, mouse driver, and VGA driver. I know Parallax already has drivers for these devices already, but I would very much·like to understand how the devices work enough so I can write a much condescended version of the code. I'm trying to fit the maximum amount of functionality in to a single propeller chip. Currently most objects that have be created by Parallax each require a single core or more·to run, I want to see if I can double up a few things.
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Thank you for your help (I'll also post responses and updates·back here to this tread for the project - I've been known to start multiple treads for new questions).

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Nyamekye

Mike Green

There is already a combined keyboard / mouse driver. You might look at that for ideas since it's basically the already existing keyboard driver and mouse driver combined. You should also look at FullDuplexSerial which already combines a receive routine and a transmit routine. There's also a 4 port serial driver.

You will not be able to add anything else to most of the VGA drivers. They already make use of most of one or more cogs for VGA video generation. It's very time and space intensive. The others can be combined in various combinations because the I/O is much slower than the capacity of the cog and the routines are not that big (except for the serial drivers).

For "how it works", look at the Wikipedia articles and their links for PS/2 keyboard and PS/2 mouse. For VGA and NTSC video, I suggest the Hydra Manual.

Kye

Ah! The Hyrda Maunal, information I have yet to read.

Thank you,

More help is appreciated!

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Nyamekye,

Kye

Back again,

I just got myself a copy of the hydra system and I'm sure I'll be able to clear up many of my questions about the chip with it.

However, I was wondering if anyone knows the speed of which the propeller can read the eeprom. I would like to actually use the eeprom for bitmap space but I do not know how fast I can get data off of it.

Thank you for your help,

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Nyamekye,

Ariba

The Spin EEPROM drivers are slow, but if you find (or make) an Assembly version, then it's the EEPROM which limits the speed.
Most EEPROM are made for 400 kHz clock, but I've seen also 1 MHz versions.
For reading a bitmap from the EEPROM you need first 3 bytes for the command and address, and then you can read contiguous bytes while the address is incremented automatically. I2C needs 9 bits per byte (8 data + 1 ACK) so at 400 kHz clock:
time = (n+3) * 9 * 2.5us
for n bytes (us = microseconds).

Andy

Edit: An SD card is much faster (up to 20MHz bit read rate) and has a lot more capacity.

Post Edited (Ariba) : 11/14/2008 1:09:35 AM GMT