Here's what the scan chain might look like for a chip more than one TAP:
@verbatim
- TapName Enabled IdCode Expected IrLen IrCap IrMask Instr
--- ------------------ ------- ---------- ---------- ----- ----- ------ -----
- 0 omap5912.dsp Y 0x03df1d81 0x03df1d81 38 0 0 0x...
- 1 omap5912.arm Y 0x0692602f 0x0692602f 4 0x1 0 0xc
- 2 omap5912.unknown Y 0x00000000 0x00000000 8 0 0 0xff
+ TapName Enabled IdCode Expected IrLen IrCap IrMask
+-- ------------------ ------- ---------- ---------- ----- ----- ------
+ 0 omap5912.dsp Y 0x03df1d81 0x03df1d81 38 0x01 0x03
+ 1 omap5912.arm Y 0x0692602f 0x0692602f 4 0x01 0x0f
+ 2 omap5912.unknown Y 0x00000000 0x00000000 8 0x01 0x03
@end verbatim
+OpenOCD can detect some of that information, but not all
+of it. @xref{Autoprobing}.
Unfortunately those TAPs can't always be autoconfigured,
because not all devices provide good support for that.
JTAG doesn't require supporting IDCODE instructions, and
exiting the OpenOCD configuration stage,
but systems with a JTAG router can
enable or disable TAPs dynamically.
-In addition to the enable/disable status, the contents of
-each TAP's instruction register can also change.
@end deffn
@c FIXME! "jtag cget" should be able to return all TAP
char expected_id[12];
tap = jtag_all_taps();
- command_print(CMD_CTX, " TapName | Enabled | IdCode Expected IrLen IrCap IrMask Instr ");
- command_print(CMD_CTX, "---|--------------------|---------|------------|------------|------|------|------|---------");
+ command_print(CMD_CTX,
+" TapName Enabled IdCode Expected IrLen IrCap IrMask");
+ command_print(CMD_CTX,
+"-- ------------------- -------- ---------- ---------- ----- ----- ------");
while (tap) {
- uint32_t expected, expected_mask, cur_instr, ii;
+ uint32_t expected, expected_mask, ii;
snprintf(expected_id, sizeof expected_id, "0x%08x",
(unsigned)((tap->expected_ids_cnt > 0)
expected = buf_get_u32(tap->expected, 0, tap->ir_length);
expected_mask = buf_get_u32(tap->expected_mask, 0, tap->ir_length);
- cur_instr = buf_get_u32(tap->cur_instr, 0, tap->ir_length);
command_print(CMD_CTX,
- "%2d | %-18s | %c | 0x%08x | %s | 0x%02x | 0x%02x | 0x%02x | 0x%02x",
+ "%2d %-18s %c 0x%08x %s %5d 0x%02x 0x%02x",
tap->abs_chain_position,
tap->dotted_name,
tap->enabled ? 'Y' : 'n',
expected_id,
(unsigned int)(tap->ir_length),
(unsigned int)(expected),
- (unsigned int)(expected_mask),
- (unsigned int)(cur_instr));
+ (unsigned int)(expected_mask));
for (ii = 1; ii < tap->expected_ids_cnt; ii++) {
snprintf(expected_id, sizeof expected_id, "0x%08x",
expected_id[2] = '*';
command_print(CMD_CTX,
- " | | | | %s | | | | ",
+ " %s",
expected_id);
}