Looking for a 2 dollar uart

I've been looking for a cheap uart for serial console/code uploading. I don't need much,

56k baud, serial or parallel interface. Don't suggest MAX3100, it's a decent part but it's a little too expensive and I'm tired of playing with Maxim if you know what I mean.

I'm tempted to spin my own, either with extra cells in a Xilinx CPLD or with a $2.50 PIC.

Any other suggestions?

Reply to
Jim Stewart
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PIC16F627A, I'd guess. $2.75 x1 and $1.57 x25, at digikey.

Or, if you can lose some of the pins on the max3100, like the /rts, /cts, /shdn, and /cs, you *might* be able to get away with a $1.68 x1 and $1.03 x25 price for the PIC12F629.

PIC12F629 _________ 1-|Vcc GND|-8 | | 2-|DIN DOUT|-7 | | 3-|SCLK /IRQ|-6 | | 4-|Rx Tx|-5 ---------

No idea what you care about there, though.

Jon

Reply to
Jonathan Kirwan

PIC12C508 or 12F629 if you want flash and/or interrupts. - should be below $1.50 in quantities more than a few. PIC will probably be more flexible than a CPLD, and it may be able to take away some processing from the main CPU, e.g. fifo buffering.

Reply to
Mike Harrison

Hi

The Philips P87LPC760 14 pin micro with on-board UART hardware and +-2.5% tolerence RC osc (suitable for some speeds).

Might do the trick

the P87LPC760 is a simple verison of the 80c51 core.

Very cheep - should come close to ~$2. in volume

Just a thought

JG

Reply to
Joseph Goldburg

An MSP430 would be smaller, cheaper and take less power. Only 3.3 V, though.

Leon

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Leon Heller, G1HSM
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Reply to
Leon Heller

Try

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Claims 99c/10K - and you get UART i2c HW support ( so meets your serial interface) and 256 Bytes of RAM allow large buffers. just ignore the 'spare resource' :) ( PCA, analog comparitor, and 1500 bytes of code space)

-jg

Reply to
Jim Granville

Thanks for all the $2 uart suggestions. I think that I'll work on the MSP430 approach.

Le>

Reply to
Jim Stewart

I'd think an 8-pin would probably be a bit cheaper.

Reply to
Mike Harrison

Hi Jim,

Well, the UART won't fit in a $2 CPLD. The UART cores we were looking at would fit in a 144 macrocell CPLD (CoolRunner if I'm not mistaken). I think the UART was about 124 macrocells by itself.

Elroy

Reply to
Elroy the Seedy Impaler

The National Semi stuff (16552) should be priced in that ballpark at moderate volume (I can get em for ~2.75 in singles), a PIC is good too, but requires someone to program it - amortize that.

Andrew

Elroy the Seedy Impaler wrote:

Reply to
Andrew Paule

On Fri, 27 Jun 2003 16:38:27 -0700, Jim Stewart wrote: >I've been looking for a cheap uart for serial >console/code uploading. I don't need much, >56k baud, serial or parallel interface. Don't >suggest MAX3100, it's a decent part but it's >a little too expensive and I'm tired of playing >with Maxim if you know what I mean. >

Current CPLD technology is not UART optimal, unless you need a special case. eg we did a design that needed many cascaded, TX only, fixed Baud, and for that CPLD was ideal.

Better would be

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They claim 99c/10K, and you have 256 Bytes of RAM for FIFO buffers, and an i2c BUS. Think of it as a MAX3100 with bigger FIFOs and a free uC :)

-jg

Reply to
Jim Granville

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