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* stk500v2.c (stk500v2_set_sck_period): Revamp this to match the 

description/pseudo-code in appnote AVR068.



git-svn-id: svn://svn.savannah.nongnu.org/avrdude/trunk/avrdude@1229 81a1dc3b-b13d-400b-aceb-764788c761c2
This commit is contained in:
joerg_wunsch 2013-09-13 21:32:00 +00:00
parent 97ca8c2e5d
commit 65a7c7daca
3 changed files with 54 additions and 24 deletions
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5
ChangeLog
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@ -1,3 +1,8 @@
2013-09-13 Joerg Wunsch <j.gnu@uriah.heep.sax.de>
* stk500v2.c (stk500v2_set_sck_period): Revamp this to match the
description/pseudo-code in appnote AVR068.
2013-09-13 Joerg Wunsch <j.gnu@uriah.heep.sax.de>
Submitted by Stephen Roe:

1
NEWS
View File

@ -112,6 +112,7 @@ Current:
- patch #7657: Add ATmega406 support for avrdude using DRAGON + JTAG
- bug #35474: Feature request: print fuse values in safemode output.
- patch #7710: usb_libusb: Check VID/PID before opening device
- [no-id]: Fix SCK period adjustment for STK500v2
* Keep track of input file contents

72
stk500v2.c
View File

@ -281,6 +281,7 @@ static int stk500v2_paged_write(PROGRAMMER * pgm, AVRPART * p, AVRMEM * m,
static unsigned int stk500v2_mode_for_pagesize(unsigned int pagesize);
static double stk500v2_sck_to_us(PROGRAMMER * pgm, unsigned char dur);
static int stk500v2_set_sck_period_mk2(PROGRAMMER * pgm, double v);
static int stk600_set_sck_period(PROGRAMMER * pgm, double v);
@ -2860,37 +2861,60 @@ static unsigned int stk500v2_mode_for_pagesize(unsigned int pagesize)
exit(1);
}
/* This code assumes that each count of the SCK duration parameter
represents 8/f, where f is the clock frequency of the STK500V2 master
processors (not the target). This number comes from Atmel
application note AVR061. It appears that the STK500V2 bit bangs SCK.
For small duration values, the actual SCK width is larger than
expected. As the duration value increases, the SCK width error
diminishes. */
/*
* See pseudo-code in AVR068
*
* This algorithm only fits for the STK500 itself. For the (old)
* AVRISP, the resulting ISP clock is only half. While this would be
* easy to fix in the algorithm, we'd need to add another
* configuration flag for this to the config file. Given the old
* AVRISP devices are virtually no longer around (and the AVRISPmkII
* uses a different algorithm below), it's probably not worth the
* hassle.
*/
static int stk500v2_set_sck_period(PROGRAMMER * pgm, double v)
{
unsigned int d;
unsigned char dur;
double min, max;
double f = 1 / v;
min = 8.0 / STK500V2_XTAL;
max = 255 * min;
dur = v / min + 0.5;
if (v < min) {
dur = 1;
fprintf(stderr,
"%s: stk500v2_set_sck_period(): p = %.1f us too small, using %.1f us\n",
progname, v / 1e-6, dur * min / 1e-6);
} else if (v > max) {
dur = 255;
fprintf(stderr,
"%s: stk500v2_set_sck_period(): p = %.1f us too large, using %.1f us\n",
progname, v / 1e-6, dur * min / 1e-6);
}
if (f >= 1.8432E6)
d = 0;
else if (f > 460.8E3)
d = 1;
else if (f > 115.2E3)
d = 2;
else if (f > 57.6E3)
d = 3;
else
d = (unsigned int)ceil(1 / (24 * f / (double)STK500V2_XTAL) - 10.0 / 12.0);
if (d >= 255)
d = 254;
dur = d;
return stk500v2_setparm(pgm, PARAM_SCK_DURATION, dur);
}
static double stk500v2_sck_to_us(PROGRAMMER * pgm, unsigned char dur)
{
double x;
if (dur == 0)
return 0.5425;
if (dur == 1)
return 2.17;
if (dur == 2)
return 8.68;
if (dur == 3)
return 17.36;
x = (double)dur + 10.0 / 12.0;
x = 1.0 / x;
x /= 24.0;
x *= (double)STK500V2_XTAL;
return 1E6 / x;
}
static int stk600_set_vtarget(PROGRAMMER * pgm, double v)
{
@ -3255,7 +3279,7 @@ static void stk500v2_print_parms1(PROGRAMMER * pgm, const char * p)
stk500v2_getparm(pgm, PARAM_OSC_PSCALE, &osc_pscale);
stk500v2_getparm(pgm, PARAM_OSC_CMATCH, &osc_cmatch);
fprintf(stderr, "%sSCK period : %.1f us\n", p,
sck_duration * 8.0e6 / STK500V2_XTAL + 0.05);
stk500v2_sck_to_us(pgm, sck_duration));
fprintf(stderr, "%sVaref : %.1f V\n", p, vadjust / 10.0);
fprintf(stderr, "%sOscillator : ", p);
if (osc_pscale == 0)