This patch adds the platform for experimentation of state path
transitions using TMS sequences shorter than 7 clocks.
It will break nothing, I promise.
If you want to experiment with the new table at line 3143 in jtag.c,
then just enable that #if statement at line 3127 and augment your
driver(s) with calls to
tap_get_tms_path_len() to determine the length of the TMS bit vector.
If you do not enable the #if at 3127, said patch will have no behavioral
effect, and should tap_get_tms_path_len() be called, it will return 7.
However said patch does add the new subject function and gives us better
maintainability for TMS sequences since they are now in binary rather
than in hex. And it puts in place a migration path for drivers that
want to minimize clock cycles.
Please commit ASAP since other patches in my queue depend on this.
Again, it will break nothing and will likely make Jeff Williams and
company happy.
Dick
Index: src/jtag/jtag.c
===================================================================
--- src/jtag/jtag.c (revision 1548)
+++ src/jtag/jtag.c (working copy)
@@ -1245,7 +1245,7 @@
bit_count = 0;
#ifdef _DEBUG_JTAG_IO_
- LOG_DEBUG("num_fields: %i",cmd->num_fields);
+ LOG_DEBUG("%s num_fields: %i", cmd->ir_scan ? "IRSCAN" : "DRSCAN", cmd->num_fields);
#endif
for (i = 0; i < cmd->num_fields; i++)
@@ -1261,10 +1261,20 @@
free(char_buf);
#endif
}
+ else
+ {
+#ifdef _DEBUG_JTAG_IO_
+ LOG_DEBUG("fields[%i].out_value[%i]: NULL", i, cmd->fields[i].num_bits);
+#endif
+ }
bit_count += cmd->fields[i].num_bits;
}
+#ifdef _DEBUG_JTAG_IO_
+ //LOG_DEBUG("bit_count totalling: %i", bit_count );
+#endif
+
return bit_count;
}
@@ -3053,14 +3063,6 @@
{
/* given a stable state, return the index into the tms_seqs[] array within tap_get_tms_path() */
- /* old version
- const static int move_map[16] =
- {
- 0, -1, -1, 2, -1, 3, -1, -1,
- 1, -1, -1, 4, -1, 5, -1, -1
- };
- */
-
int ndx;
switch( astate )
@@ -3079,48 +3081,109 @@
return ndx;
}
-int tap_get_tms_path( tap_state_t from, tap_state_t to )
+
+/* tap_move[i][j]: tap movement command to go from state i to state j
+ * 0: Test-Logic-Reset
+ * 1: Run-Test/Idle
+ * 2: Shift-DR
+ * 3: Pause-DR
+ * 4: Shift-IR
+ * 5: Pause-IR
+ *
+ * DRSHIFT->DRSHIFT and IRSHIFT->IRSHIFT have to be caught in interface specific code
+ */
+static struct
{
- /* tap_move[i][j]: tap movement command to go from state i to state j
- * 0: Test-Logic-Reset
- * 1: Run-Test/Idle
- * 2: Shift-DR
- * 3: Pause-DR
- * 4: Shift-IR
- * 5: Pause-IR
- *
- * DRSHIFT->DRSHIFT and IRSHIFT->IRSHIFT have to be caught in interface specific code
+ u8 bits;
+ u8 bit_count;
+
+} tms_seqs[6][6] = /* [from_state_ndx][to_state_ndx] */
+{
+ /* value clocked to TMS to move from one of six stable states to another.
+ * N.B. OOCD clocks TMS from LSB first, so read these right-to-left.
+ * N.B. These values are tightly bound to the table in tap_get_tms_path_len().
+ * N.B. Reset only needs to be 0b11111, but in JLink an even byte of 1's is more stable.
+ * These extra ones cause no TAP state problem, because we go into reset and stay in reset.
*/
- static const u8 tms_seqs[6][6] =
- {
- /* value clocked to TMS to move from one of six stable states to another */
- /* RESET IDLE DRSHIFT DRPAUSE IRSHIFT IRPAUSE */
- { 0x7f, 0x00, 0x17, 0x0a, 0x1b, 0x16 }, /* RESET */
- { 0x7f, 0x00, 0x25, 0x05, 0x2b, 0x0b }, /* IDLE */
- { 0x7f, 0x31, 0x00, 0x01, 0x0f, 0x2f }, /* DRSHIFT */
- { 0x7f, 0x30, 0x20, 0x17, 0x1e, 0x2f }, /* DRPAUSE */
- { 0x7f, 0x31, 0x07, 0x17, 0x00, 0x01 }, /* IRSHIFT */
- { 0x7f, 0x30, 0x1c, 0x17, 0x20, 0x2f } /* IRPAUSE */
- };
+/*
+ * These macros allow us to specify TMS state transitions by bits rather than hex bytes.
+ * Read the bits from LSBit first to MSBit last (right-to-left).
+ */
+#define HEX__(n) 0x##n##LU
- if( !tap_is_state_stable(from) )
- {
- LOG_ERROR( "fatal: tap_state \"from\" (=%s) is not stable", tap_state_name(from) );
- exit(1);
- }
+#define B8__(x) \
+ (((x) & 0x0000000FLU)?(1<<0):0) \
+ +(((x) & 0x000000F0LU)?(1<<1):0) \
+ +(((x) & 0x00000F00LU)?(1<<2):0) \
+ +(((x) & 0x0000F000LU)?(1<<3):0) \
+ +(((x) & 0x000F0000LU)?(1<<4):0) \
+ +(((x) & 0x00F00000LU)?(1<<5):0) \
+ +(((x) & 0x0F000000LU)?(1<<6):0) \
+ +(((x) & 0xF0000000LU)?(1<<7):0)
- if( !tap_is_state_stable(to) )
- {
- LOG_ERROR( "fatal: tap_state \"to\" (=%s) is not stable", tap_state_name(to) );
- exit(1);
- }
+#define B8(bits,count) { ((u8)B8__(HEX__(bits))), (count) }
- /* @todo: support other than 7 clocks ? */
- return tms_seqs[tap_move_ndx(from)][tap_move_ndx(to)];
+#if 0 && ((BUILD_FT2232_FTD2XX==1) || (BUILD_FT2232_LIBFTDI==1))
+ /* this is the table submitted by Jeff Williams on 3/30/2009 with this comment:
+
+ OK, I added Peter's version of the state table, and it works OK for
+ me on MC1322x. I've recreated the jlink portion of patch with this
+ new state table. His changes to my state table are pretty minor in
+ terms of total transitions, but Peter feels that his version fixes
+ some long-standing problems.
+ Jeff
+
+ I added the bit count into the table
+ Dick
+ */
+
+ /* to state: */
+ /* RESET IDLE DRSHIFT DRPAUSE IRSHIFT IRPAUSE */ /* from state: */
+ { B8(11111,5), B8(0,1), B8(0010,4), B8(01010,5), B8(00110,5), B8(010110,6) }, /* RESET */
+ { B8(11111,5), B8(0,1), B8(001,3), B8(0101,4), B8(0011,4), B8(01011,5) }, /* IDLE */
+ { B8(11111,5), B8(011,3), B8(00111,5), B8(01,2), B8(001111,6), B8(0101111,7) }, /* DRSHIFT */
+ { B8(11111,5), B8(011,3), B8(01,2), B8(0,1), B8(001111,6), B8(0101111,7) }, /* DRPAUSE */
+ { B8(11111,5), B8(011,3), B8(00111,5), B8(010111,6), B8(001111,6), B8(01,2) }, /* IRSHIFT */
+ { B8(11111,5), B8(011,3), B8(00111,5), B8(010111,6), B8(01,2), B8(0,1) } /* IRPAUSE */
+
+#else /* this is the old table, converted from hex and with the bit_count set to 7 for each combo, like before */
+
+ /* to state: */
+ /* RESET IDLE DRSHIFT DRPAUSE IRSHIFT IRPAUSE */ /* from state: */
+ { B8(1111111,7), B8(0000000,7), B8(0010111,7), B8(0001010,7), B8(0011011,7), B8(0010110,7) }, /* RESET */
+ { B8(1111111,7), B8(0000000,7), B8(0100101,7), B8(0000101,7), B8(0101011,7), B8(0001011,7) }, /* IDLE */
+ { B8(1111111,7), B8(0110001,7), B8(0000000,7), B8(0000001,7), B8(0001111,7), B8(0101111,7) }, /* DRSHIFT */
+ { B8(1111111,7), B8(0110000,7), B8(0100000,7), B8(0010111,7), B8(0011110,7), B8(0101111,7) }, /* DRPAUSE */
+ { B8(1111111,7), B8(0110001,7), B8(0000111,7), B8(0010111,7), B8(0000000,7), B8(0000001,7) }, /* IRSHIFT */
+ { B8(1111111,7), B8(0110000,7), B8(0011100,7), B8(0010111,7), B8(0100000,7), B8(0101111,7) } /* IRPAUSE */
+
+#endif
+
+#if 0 /* keeping old hex stuff for awhile, for reference */
+ /* RESET IDLE DRSHIFT DRPAUSE IRSHIFT IRPAUSE */
+ { 0x7f, 0x00, 0x17, 0x0a, 0x1b, 0x16 }, /* RESET */
+ { 0x7f, 0x00, 0x25, 0x05, 0x2b, 0x0b }, /* IDLE */
+ { 0x7f, 0x31, 0x00, 0x01, 0x0f, 0x2f }, /* DRSHIFT */
+ { 0x7f, 0x30, 0x20, 0x17, 0x1e, 0x2f }, /* DRPAUSE */
+ { 0x7f, 0x31, 0x07, 0x17, 0x00, 0x01 }, /* IRSHIFT */
+ { 0x7f, 0x30, 0x1c, 0x17, 0x20, 0x2f } /* IRPAUSE */
+#endif
+};
+
+
+int tap_get_tms_path( tap_state_t from, tap_state_t to )
+{
+ return tms_seqs[tap_move_ndx(from)][tap_move_ndx(to)].bits;
}
+int tap_get_tms_path_len( tap_state_t from, tap_state_t to )
+{
+ return tms_seqs[tap_move_ndx(from)][tap_move_ndx(to)].bit_count;
+}
+
+
bool tap_is_state_stable(tap_state_t astate)
{
bool is_stable;
@@ -3250,7 +3313,7 @@
switch( state )
{
case TAP_RESET: ret = "RESET"; break;
- case TAP_IDLE: ret = "RUN/IDLE"; break;
+ case TAP_IDLE: ret = "RUN/IDLE"; break;
case TAP_DRSELECT: ret = "DRSELECT"; break;
case TAP_DRCAPTURE: ret = "DRCAPTURE"; break;
case TAP_DRSHIFT: ret = "DRSHIFT"; break;
Index: src/jtag/jtag.h
===================================================================
--- src/jtag/jtag.h (revision 1548)
+++ src/jtag/jtag.h (working copy)
@@ -181,7 +181,26 @@
*/
int tap_get_tms_path(tap_state_t from, tap_state_t to);
+
/**
+ * Function int tap_get_tms_path_len
+ * returns the total number of bits that represents a TMS path
+ * transition as given by the function tap_get_tms_path().
+ *
+ * For at least one interface (JLink) it's not OK to simply "pad" TMS sequences
+ * to fit a whole byte. (I suspect this is a general TAP problem within OOCD.)
+ * Padding TMS causes all manner of instability that's not easily
+ * discovered. Using this routine we can apply EXACTLY the state transitions
+ * required to make something work - no more - no less.
+ *
+ * @param from is the starting state
+ * @param to is the resultant or final state
+ * @return int - the total number of bits in a transition.
+ */
+int tap_get_tms_path_len(tap_state_t from, tap_state_t to);
+
+
+/**
* Function tap_move_ndx
* when given a stable state, returns an index from 0-5. The index corresponds to a
* sequence of stable states which are given in this order: <p>
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