Hi Leon,
I'm "on the air" now too with LPC2106 !
Here is a prelim. current consumption figure I took
:
I measure 6.5 mA @ 10 MHz setting and clearing P0.0 in a
loop
(PLL default bypassed and 1 cclk /
fetch) executing out of Flash.
Pretty impressive !
Trying to execute this as fast as possible has lifted up the
veil a bit better on some of the instructions,
but there is still a mystery,
so a question for people that are much more intimate
with ARM7/LPC,
( I don't feel like asking an FAE
that won't know an answer anyway and I can't find it
in the
ARM7TDMI ref manual) :
I noticed it seems the VPB bus either causes
inserted NOPs in the pipeline, or wait states are
automatically generated when I "write too fast" to the VPB
bus.
Furthermore , I'm not even generating Read/Modify/Write
instructions with my test C code !!!! ????
;
The 2nd question is, what if I write at a slower rate to
VPB ?
Do I still need the fastest pclk for my I/O pins to update as fast as possible ?????
(I can't trace :-)
As an example, C code generating this sequence :
.......
STR R4,[R7,#0]
P0.0 set to "1"
MOV R4,#1
STR R4,[R0,#0]
; P0.0 set to "0"
......
Takes :
1.6 uS (16 cclks) with pclk = 4 cclks
1.0 uS (10 cclks) with pclk = 2 cclks
0.8 uS (8 cclks) with pclk = 1 cclks
(that's what I measure here on HW)
Is there anyone that can shed some light on this
?
toggling P0.0 with pclk = cclk/4
-- Kris
----- Original Message -----
From: "Leon Heller" <leon_heller@...>
To: <lpc2100@yahoogroups.com>
Sent: Saturday, November 22, 2003 9:49 PM
Subject: [lpc2100] Simple test program