at91sam3XXX.cfg: Configure JTAG clock to 500 kHz.

[fw/openocd] / tcl / target / at91sam3XXX.cfg

diff --git a/tcl/target/at91sam3XXX.cfg b/tcl/target/at91sam3XXX.cfg
index a13e39901368f74464790ee7f17c559d86bf0d60..98b508c42c1a6729ee6ec4c752db4df173ac224a 100644 (file)
--- a/tcl/target/at91sam3XXX.cfg
+++ b/tcl/target/at91sam3XXX.cfg
@@ -29,6 +29,18 @@ if { [info exists ENDIAN] } {
    set _ENDIAN little
 }
 
+# JTAG speed should be <= F_CPU/6. F_CPU after reset is 4 MHz, so use F_JTAG = 0.5MHz
+#
+# Since we may be running of an RC oscilator, we crank down the speed a
+# bit more to be on the safe side. Perhaps superstition, but if are
+# running off a crystal, we can run closer to the limit. Note
+# that there can be a pretty wide band where things are more or less stable.
+
+adapter_khz 500
+
+adapter_nsrst_delay 100
+jtag_ntrst_delay 100
+
 #jtag scan chain
 if { [info exists CPUTAPID] } {
    set _CPUTAPID $CPUTAPID