Two ports, one 6 bit control port and one 8 bit io port. The power up reading of the control port (with weak pull up's) tells the UNIO what mode to operate in. Modes that do not use all 6 control port lines are identified because they have the left over lines pulled (or jumpered) low on the circuit board.
|111111||En, Addr, Data||4 bit by two addressable latch|
|011111||-, Addr, Data||4 bit by two addressable latch||Lack of clock is compinsated for by watching all lines for 0.5 clock cycles after any change is detected and updateing output pins only after this "settleing time"|
|1110 11||En, Data, -, Addr||2 bit by four addressable latch|
|0110 11||-, Data, Addr||2 bit by four addressable latch|
|101 111||En, -, Data, Addr[0..3]||1 bit by eight addressable latch|
|010 111||-, Data, -, Addr[0..3]||1 bit by eight addressable latch|
|1111 10||SCK, SI, SO, *CE, 1, 0||SPI|
|1011 10||SCK, -, SI+SO, CE, 1, 0||SPI (3 pin)||SO connected to SI thru resistor|
|1111 00||SCK, SI, SO, CE, 0, 0||SPI <-> Serial||RX, TX, *CE, are the first three pins of the 8 bit IO port|
|1111 01||SCK, SI, SO, CE, 0, 1||SPI <-> I2C||SCL, SDA, -, *CE are the first four pins of the 8 bit IO port.|
|1100 01||SCL, SDA, -, -, 0, 1||I2C||Basically a shift register|
|1101 01||SCL, SDA, -, *CE, 0, 1||I2C with *CE||Several shift registers connect to the same data and clock lines with seperate chip selects|
|1111 01||SCL, SDA, CLR, *CE, 0, 1||I2C with *CE and CLR||Shift register with enable and clear.|
|1101 00||SCL, SDA, -,*CE, 0 , 0||I2C <-> Serial||Allows us to debug I2C interfaces.
|0100 00||-, TX, -, -, 0, 0||Serial Out|
|1000 00||RX, -, -, -, 0, 0||Serial In|
|0110 00||-, TX,*CE, -, 0, 0||Serial Out with *CE|
|1010 00||RX, -, *CE, -, 0, 0||Serial In with *CE|
|1100 00||RX, TX, -, -, 0, 0||Serial IO|
|1110 00||RX, TX, *CE, -, 0, 0||Serial IO with *CE|
Notice that the first line of the 6 bit control port is the IRQ line.
|file: /Techref/idea/unio.htm, 4KB, , updated: 2002/5/6 16:26, local time: 2018/3/18 06:28,
|©2018 These pages are served without commercial sponsorship. (No popup ads, etc...).Bandwidth abuse increases hosting cost forcing sponsorship or shutdown. This server aggressively defends against automated copying for any reason including offline viewing, duplication, etc... Please respect this requirement and DO NOT RIP THIS SITE. Questions?|
<A HREF="http://www.piclist.com/techref/idea/unio.htm"> Universal IO expander, UNIO</A>
|Did you find what you needed?|
PICList 2018 contributors:
o List host: MIT, Site host massmind.org, Top posters @20180318 RussellMc, Isaac M. Bavaresco, Sean Breheny, Neil, Van Horn, David, David C Brown, alan.b.pearce, Bob Blick, John Gardner, Brent Brown,
* Page Editors: James Newton, David Cary, and YOU!
* Roman Black of Black Robotics donates from sales of Linistep stepper controller kits.
* Ashley Roll of Digital Nemesis donates from sales of RCL-1 RS232 to TTL converters.
* Monthly Subscribers: Gregg Rew. on-going support is MOST appreciated!
* Contributors: Richard Seriani, Sr.
Welcome to www.piclist.com!