UM0193
Hardware
Figure 10.
JTAG schematic diagram
1.6.1
JTAG supply voltages
A +3.3V DC supply voltage placed on pins 1 and 2 is provided by the DC/DC converter (U6)
reference pin or a separate linear voltage regulator (U7). Please verify the consumption of
any device (for example, converter box) connected to this connector. According to the
device datasheet, the reference pin can deliver a maximum current of 5mA, providing an
accurate voltage level. If the consumption is higher, select the linear voltage regulator (U7)
for the supply connector using jumper J33 as described in
Certain converter boxes provide a +5V DC supply voltage for the JTAG interface. The new
generation J-link from IAR Systems (the yellow one) provides the supply voltage on pin
number 19. For applications using supplies from the converter box, connect a wire from pin
number 19 of the JTAG (J7) connector to c5V DC supply point (for example, J19
right pin). For JTAG communication functions, jumper J32 must be connected and jumper
J33 set to the "lin" position when a +5V DC voltage supply is used.
Caution:
Using a supply from a converter box is not recommended for application development or
testing. Accidental short-circuits may damage USB host or converter box circuits.
Table 7.
JTAG connections
Pin
Signal
Pin
Signal
1
+3.3V DC
2
+3.3V DC
3
JTRST
4
GND
5
JTDI
6
GND
7
JTMS
8
GND
9
JTCK
10
GND
11
Connected to GND by R18 (10k
Ω
)
12
GND
13
JTDO
14
GND
15
RESET
16
GND
17
Connected to GND by R20 (10k
Ω
)
18
GND
19
Connected to GND by R21 (10k
Ω
)
20
GND
Ai11699
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
3V3
3V3
3V3
3V3
3V3
3V3
3V3
3V3
C51
100 nF
3V3
C18
100 nF
3V3
C52
10M/16V
+
CON20A
3V3
J7
R18
10k
R19
10k
R20
10k
R21
10k
D2
BZX84C3V3/SOT
R17 430R
nJTRST
JTDI
JTMS
JTCK
JTDO
nRST_EXT
R11
10k
NA
R12
10k
R13
10k
R14
10k
R15
10k
NA
R16
10k
NA
