Report if TDO seems to be stuck during detect_register_size (ie. "detect")

git-svn-id: https://urjtag.svn.sourceforge.net/svnroot/urjtag/trunk@1018 b68d4a1b-bc3d-0410-92ed-d4ac073336b7

jtag/include/register.h

@@ -37,6 +37,7 @@ tap_register *register_duplicate( const tap_register_t *tr );
 void register_free( tap_register_t *tr );
 tap_register *register_fill( tap_register_t *tr, int val );
 const char *register_get_string( const tap_register_t *tr );
+int register_all_bits_same_value( const tap_register_t *tr );
 tap_register *register_init( tap_register_t *tr, const char *value );
 int register_compare( const tap_register_t *tr, const tap_register_t *tr2 );
 int register_match( const tap_register_t *tr, const char *expr );

jtag/src/discovery.c

@@ -46,6 +46,9 @@ detect_register_size( chain_t *chain )
 	tap_register *rout;
 	tap_register *rpat;
 
+	/* This seems to be a good place to check if TDO changes at all */
+	int tdo, tdo_stuck = -2;
+
 	for (len = 1; len <= MAX_REGISTER_LENGTH; len++) {
 		int p;
 		int ok = 0;
@@ -67,6 +70,10 @@ detect_register_size( chain_t *chain )
 				tap_shift_register( chain, rz, NULL, 0 );
 				tap_shift_register( chain, rpat, rout, 0 );
 
+				tdo = register_all_bits_same_value(rout);
+				if(tdo_stuck == -2) tdo_stuck = tdo;
+				if(tdo_stuck != tdo) tdo_stuck = -1;
+
 				register_shift_right( rout, len );
 
 				if (register_compare( rpat, rout ) == 0)
@@ -88,6 +95,11 @@ detect_register_size( chain_t *chain )
 			return len;
 	}
 
+	if(tdo_stuck >= 0)
+	{
+		printf(_("Warning: TDO seems to be stuck at %d\n"), tdo_stuck);
+	}
+
 	return -1;
 }
 

jtag/src/tap/register.c

@@ -102,6 +102,25 @@ register_get_string( const tap_register *tr )
 	return tr->string;
 }
 
+int
+register_all_bits_same_value ( const tap_register *tr )
+{
+	int i, value;
+	if (!tr) return -1;
+	if (tr->len < 0) return -1;
+
+	/* Return -1 if any of the bits in the register
+	 * differs from the others; the value otherwise. */
+
+	value = tr->data[0] & 1;
+
+	for(i=1; i<tr->len; i++)
+	{
+		if((tr->data[i] & 1) != value) return -1;
+	}
+	return value;
+}
+
 tap_register *
 register_init( tap_register *tr, const char *value )
 {