Yahoo Groups archive
Thread
2004-01-12 by frankpoplonski
Hi all, short info about Pin Connect Block setup tool in the download area. Description: easy way to setup Pin Connect Block for LPC210x OS: tested with Win XP, Win 98 Output: generates a INI function for Pin Connect Block Tested with Keil ARM (gcc) tools and Keil lpc210x.h Version: 1.00 Beta Licence: freeware Author: Frank Poplonski fpo@... -- Frank
2004-01-12 by Curt Powell
We are interfacing to a peripheral usb chip and have come up with a limitation that I'm having difficulty overcoming so I thought I'd post this to the group to see if anyone has any suggestions. Basically, when a READY pin goes high, the usb chip requires us to initiate the followon write (by driving a WRITE pin low) within 360 nanoseconds. Even writing in assembler, about the best I can consistently do (detecting READY high and driving WRITE low) is 500+ns. If anyone can suggest a trick to speed this up I'd appreciate their input. (BTW, we are running the CPU at 59+Mhz and vpb divider is 2) Curt
2004-01-12 by Bill Knight
Curt Try connecting the READY line to an EINT pin configured as the ONLY FIQ interrupt, then place the ACTUAL code for the FIQ service routine (not the LDR PC,... instruction) in RAM at 0x001C. -Bill Knight R O SoftWare On Mon, 12 Jan 2004 10:26:09 -0800, Curt Powell wrote: We are interfacing to a peripheral usb chip and have come up with a limitation that I'm having difficulty overcoming so I thought I'd post this to the group to see if anyone has any suggestions. Basically, when a READY pin goes high, the usb chip requires us to initiate the followon write (by driving a WRITE pin low) within 360 nanoseconds. Even writing in assembler, about the best I can consistently do (detecting READY high and driving WRITE low) is 500+ns. If anyone can suggest a trick to speed this up I'd appreciate their input. (BTW, we are running the CPU at 59+Mhz and vpb divider is 2) Curt
2004-01-12 by Curt Powell
Bill, A good thought. But isn't EINTx active low? I need to detect low to high. Curt
-----Original Message----- From: Bill Knight [mailto:BillK@...] Sent: Monday, January 12, 2004 11:22 AM To: lpc2100@yahoogroups.com Subject: Re: [lpc2100] Pin detection/driving Curt Try connecting the READY line to an EINT pin configured as the ONLY FIQ interrupt, then place the ACTUAL code for the FIQ service routine (not the LDR PC,... instruction) in RAM at 0x001C. -Bill Knight R O SoftWare On Mon, 12 Jan 2004 10:26:09 -0800, Curt Powell wrote: We are interfacing to a peripheral usb chip and have come up with a limitation that I'm having difficulty overcoming so I thought I'd post this to the group to see if anyone has any suggestions. Basically, when a READY pin goes high, the usb chip requires us to initiate the followon write (by driving a WRITE pin low) within 360 nanoseconds. Even writing in assembler, about the best I can consistently do (detecting READY high and driving WRITE low) is 500+ns. If anyone can suggest a trick to speed this up I'd appreciate their input. (BTW, we are running the CPU at 59+Mhz and vpb divider is 2) Curt _____ Yahoo! Groups Links * To visit your group on the web, go to: http://groups.yahoo.com/group/lpc2100/ * To unsubscribe from this group, send an email to: lpc2100-unsubscribe@yahoogroups.com <mailto:lpc2100-unsubscribe@yahoogroups.com?subject=Unsubscribe> * Your use of Yahoo! Groups is subject to the Yahoo! Terms of Service <http://docs.yahoo.com/info/terms/> .
2004-01-12 by Bill Knight
Curt Actually, I don't know. I don't have an LPC to work with and could not find the info in the docs either. I have been doing ARM development for a while and the "trick" with the FIQ is well known. In your case however, it might require the use of an inverter. -Bill On Mon, 12 Jan 2004 11:31:19 -0800, Curt Powell wrote: Bill, A good thought. But isn't EINTx active low? I need to detect low to high. Curt
-----Original Message----- From: Bill Knight [mailto:BillK@...] Sent: Monday, January 12, 2004 11:22 AM To: lpc2100@yahoogroups.com Subject: Re: [lpc2100] Pin detection/driving Curt Try connecting the READY line to an EINT pin configured as the ONLY FIQ interrupt, then place the ACTUAL code for the FIQ service routine (not the LDR PC,... instruction) in RAM at 0x001C. -Bill Knight R O SoftWare
2004-01-12 by Bill Knight
Found it. The docs state the EINT pins are active LOW and are LEVEL sensitive. -Bill
2004-01-12 by Curt Powell
Bill, Do the ARM developers use any particular inverter? Curt
-----Original Message----- From: Bill Knight [mailto:BillK@...] Sent: Monday, January 12, 2004 12:25 PM To: lpc2100@yahoogroups.com Subject: RE: [lpc2100] Pin detection/driving Curt Actually, I don't know. I don't have an LPC to work with and could not find the info in the docs either. I have been doing ARM development for a while and the "trick" with the FIQ is well known. In your case however, it might require the use of an inverter. -Bill On Mon, 12 Jan 2004 11:31:19 -0800, Curt Powell wrote: Bill, A good thought. But isn't EINTx active low? I need to detect low to high. Curt -----Original Message----- From: Bill Knight [mailto:BillK@...] Sent: Monday, January 12, 2004 11:22 AM To: lpc2100@yahoogroups.com Subject: Re: [lpc2100] Pin detection/driving Curt Try connecting the READY line to an EINT pin configured as the ONLY FIQ interrupt, then place the ACTUAL code for the FIQ service routine (not the LDR PC,... instruction) in RAM at 0x001C. -Bill Knight R O SoftWare Yahoo! Groups Sponsor ADVERTISEMENT <http://rd.yahoo.com/SIG=12c5j7n17/M=267637.4116730.5333196.1261774/D=eg roupweb/S=1706554205:HM/EXP=1074025515/A=1853619/R=0/*http://www.netflix .com/Default?mqso=60178356&partid=4116730> click here <http://us.adserver.yahoo.com/l?M=267637.4116730.5333196.1261774/D=egrou pmail/S=:HM/A=1853619/rand=898713806> _____ Yahoo! Groups Links * To visit your group on the web, go to: http://groups.yahoo.com/group/lpc2100/ * To unsubscribe from this group, send an email to: lpc2100-unsubscribe@yahoogroups.com <mailto:lpc2100-unsubscribe@yahoogroups.com?subject=Unsubscribe> * Your use of Yahoo! Groups is subject to the Yahoo! Terms of Service <http://docs.yahoo.com/info/terms/> .
2004-01-12 by Bill Knight
Not one in particular. Main things to look for are reasonably fast, and 3.3v capable. I'm sure there are a bunch. Check with your hardware engineers. There may already be a spare on the board. If not, there are some new single gate versions though I have never used them. -Bill On Mon, 12 Jan 2004 13:26:35 -0800, Curt Powell wrote: Bill, Do the ARM developers use any particular inverter? Curt