From 9977f1ed129573f6e3a0365cee50fb470b76e26c Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?=C5=81ukasz=20Stelmach?= <stlman@poczta.fm>
Date: Thu, 20 Oct 2022 19:43:45 +0200
Subject: [PATCH 1/2] Document meaning of -F during initialization
---
src/avrdude.1 | 2 ++
src/doc/avrdude.texi | 2 ++
2 files changed, 4 insertions(+)
diff --git a/src/avrdude.1 b/src/avrdude.1
index ba5292ee..5ed09b79 100644
--- a/src/avrdude.1
+++ b/src/avrdude.1
@@ -507,6 +507,8 @@ actual connection to a target controller), this option can be used
together with
.Fl t
to continue in terminal mode.
+Moreover, the option allows to continue despite failed initialization
+of connection between a programmer and a target.
.It Fl i Ar delay
For bitbang-type programmers, delay for approximately
.Ar delay
diff --git a/src/doc/avrdude.texi b/src/doc/avrdude.texi
index 1e139234..d2e9d9df 100644
--- a/src/doc/avrdude.texi
+++ b/src/doc/avrdude.texi
@@ -598,6 +598,8 @@ Also, for programmers like the Atmel STK500 and STK600 which can
adjust parameters local to the programming tool (independent of an
actual connection to a target controller), this option can be used
together with @option{-t} to continue in terminal mode.
+Moreover, the option allows to continue despite failed initialization
+of connection between a programmer and a target.
@item -i @var{delay}
For bitbang-type programmers, delay for approximately
From c890ff90ebff2fe9ad6573d1114e9fc995ef921e Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?=C5=81ukasz=20Stelmach?= <stlman@poczta.fm>
Date: Thu, 20 Oct 2022 17:34:21 +0200
Subject: [PATCH 2/2] Mention -B in the error message
One of possible problems of failed initialization is too hight frequency
of ISP clock. Mention using -B option as a possible solution.
Closes #1133
---
src/doc/avrdude.texi | 13 +++++++------
src/main.c | 5 +++--
2 files changed, 10 insertions(+), 8 deletions(-)
diff --git a/src/doc/avrdude.texi b/src/doc/avrdude.texi
index d2e9d9df..ea892e1c 100644
--- a/src/doc/avrdude.texi
+++ b/src/doc/avrdude.texi
@@ -3046,14 +3046,15 @@ See also: @url{http://www.libusb.org/ticket/6}
@item
Problem: after flashing a firmware that reduces the target's clock
speed (e.g. through the @code{CLKPR} register), further ISP connection
-attempts fail.
+attempts fail. Or a programmer cannot initialize communication with
+a brand new chip.
Solution: Even though ISP starts with pulling @var{/RESET} low, the
-target continues to run at the internal clock speed as defined by the
-firmware running before. Therefore, the ISP clock speed must be
-reduced appropriately (to less than 1/4 of the internal clock speed)
-using the -B option before the ISP initialization sequence will
-succeed.
+target continues to run at the internal clock speed either as defined by
+the firmware running before or as set by the factory. Therefore, the
+ISP clock speed must be reduced appropriately (to less than 1/4 of the
+internal clock speed) using the -B option before the ISP initialization
+sequence will succeed.
As that slows down the entire subsequent ISP session, it might make
sense to just issue a @emph{chip erase} using the slow ISP clock
diff --git a/src/main.c b/src/main.c
index 73b0a25c..49807809 100644
--- a/src/main.c
+++ b/src/main.c
@@ -1190,9 +1190,10 @@ int main(int argc, char * argv [])
init_ok = (rc = pgm->initialize(pgm, p)) >= 0;
if (!init_ok) {
pmsg_error("initialization failed, rc=%d\n", rc);
+ imsg_error("- double check the connections and try again\n");
+ imsg_error("- use -B to set lower ISP clock frequency, e.g. -B 200kHz\n");
if (!ovsigck) {
- imsg_error("double check connections and try again or use -F to override\n");
- imsg_error("this check\n\n");
+ imsg_error("- use -F to override this check\n\n");
exitrc = 1;
goto main_exit;
}