Hello,
I am Building a Embedded Controller,which has 40+ IO's and need 8 Channel ADC. I have designed it using 89c51/52 and 8255's. But i am trying to build the same in a single chip provided 48 io's. ADC(optional),UART(reqd). Constraint is that i have a programmer which supports only 48 DIP packages. Would be helpful if anybody can guide me in selecting a Chip and a programmer(Cost Effective!). Package - Any. Any guides/reference for how to program this IC http://www.keil.com/dd/chip/3449.htm
I am Building a Embedded Controller,which has 40+ IO's and need 8 Channel ADC. I have designed it using 89c51/52 and 8255's. But i am trying to build the same in a single chip provided 48 io's. ADC(optional),UART(reqd). do not stay in the past 1) get rid of the 8255 it is WAAAY too slow for modern uCs and better solutions have been available for at least the last 10 years. 2) for extreme numbers of I/O use an 8-port '51 (8*8 = 64 I/O) such as the SILabs f12x/f13x
Erik
all ISP is dead simple: provide the connection, use the manufacturer provided software
ISP is a NEW TERM for me. At the same time,i just dont wanna use an high end mC for the application.
ISP is not "high end" the <$0.50 (in volume) NXP LPC chips are ISP
Google isn't the wrong place, since it's a map of the available information, i.e. will direct to Silabs etc. It's just up to the user to make own decisions about how trustworthy different sites Google lists really are.
Anyway - a chip with 50 or 100 GPIO is not a high-end processor if looking at some architectures. The availability - and potential cost - of 8051 chips with many GPIO can be very strong reasons to consider other architectures.
"'many GPIO' can be very strong reasons to consider other architectures"
and the requirement here is not just 'many GPIO' but also quite a few analogue inputs!
And that's before even considering the processing requirements of the application...
8 ADC inputs isn't so much, but 8 ADC inputs while still having enough GPIO means the chip needs quite a lot of pins to start with. 48 + 8 = 56. Then crystal oscillator + VCC + GND + (most probably) analog Vref + reset + ...
And the ISP may require dedicated pins - either because the chip requires it, or because the external hardware connected to the GPIO pins are incompatible with the ISP requirements.
But 64, 68, 80 or maybe 100 pins _and_ 8 ADC inputs and potentially other requirements will quickly shrink the number of cheap 8051 chips. While it is still close to entry-level for ARM chips. And the price overlap between 8051 and ARM chips is huge.
The important thing is that the price of a chip is not directly proportional to number of GPIO or amount of RAM or number of ADC. A low-end version from a larger family can often be way cheaper than a high-end chip from another family. And when there are multiple manufacturers who have suitable chips, then there may be a huge price difference between the different manufacturers or sometimes between different generations from the same manufacturer.
But an important thing is that selecting a high-end version from a specific manufacturer may be a bit dangerous if the product needs to live for a long time. The bulk of sales are normally of cheaper chip versions, so the high-end (and less common) model may be dropped because it isn't economical to keep. Getting a low-end model dropped often means that slighly larger chips can be found - and often at same or lower price than what the low-end model was originally introduced at.
Here's an article extolling the virtues of Cortex-M microcontrollers:
www.emcu.it/.../WhyUsingCortexMx.html
Obviously it is promoting the parts - it's not an impartial review - but it should give you some idea of what's available in today's market...