14-pin JTAG header
Usual pin-out for 14-pin JTAG header (often used for ARM)
1 -Vddh (+3.3v)
2 - Vss (ground)
3 - nTRST
4 - Vss (ground)
5 - TDI
6 -Vss (ground)
7 - TMS
8 -Vss (ground)
9 - TCK
10-Vss (ground)
11- TDO
12-nRESET (optional)
13- Vddh (+3.3v)
14-Vss (ground)
20-pin JTAG header
Usual pin-out for 20-pin JTAG header (sometimes used for ARM)
1 - Vddh (+3.3v)
2 - Vddh (+3.3v)
3 - nTRST
4-Vss (ground)
5 - TDI
6-Vss (ground)
7 - TMS
8-Vss (ground)
9 - TCK
10-Vss (ground)
11

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12-Vss (ground)
13 –TDO
14-Vss (ground)
15 – nRST
16-Vss (ground)
17---------
18-Vss (ground)
19---------
20-Vss (ground)
8-pin JTAG header
Usual pin-out for 8-pin JTAG header, often used for PLD programming
1 – vddh (+3.3v)
2 – TDO
3 – TDI
4 – nTRST
5
6 – TMS
7 – vss (ground)
8 – TCK