4
(AD0) PA0
51
(AD1) PA1
50
(AD2) PA2
49
(AD3) PA3
48
(AD4) PA4
47
(AD5) PA5
46
(AD6) PA6
45
(AD7) PA7
44
(ALE) PG2
43
(A8) PC0
35
(A9) PC1
36
(A10) PC2
37
(A11) PC3
38
(A12) PC4
39
(A13) PC5
40
(A14) PC6
41
(A15) PC7
42
(RD) PG1
34
(WR) PG0
33
PF0 (ADC0)
61
PF1 (ADC1)
60
PF2 (ADC2)
59
PF3 (ADC3)
58
PF4 (ADC4 / TCK)
57
PF5 (ADC5 / TMS)
56
PF6 (ADC6 / TDO)
55
PF7 (ADC7 / TDI)
54
AREF
62
AGND
63
AVCC
64
PE0 (PDI / RXD0)
2
PE1 (PDO / TXD0)
3
PE2 (AC+ / XCK0)
4
PE3 (AC- / OC3A)
5
PE4 (INT4 / OC3B)
6
PE5 (INT5 / OC3C)
7
PE6 (INT6 / T3)
8
PE7 (INT7 / IC3)
9
PB0 ( SS )
10
PB1 (SCK)
11
PB2 (MOSI)
12
PB3 (MISO)
13
PB4 (OC0)
14
PB5 (OC1A)
15
PB6 (OC1B)
16
PB7 (OC2 / OC1C)
17
(INT0 / SCL) PDO
25
(INT1 / SDA) PD1
26
(INT2 / RXD1) PD2
27
(INT3 / TXD1) PD3
28
(IC1) PD4
29
(XCK1) PD5
30
(T1) PD6
31
(T2) PD7
32
XTAL2
23
XTAL1
24
G
N
D
53
G
N
D
22
V
C
C
21
V
C
C
52
PEN
1
RESET
20
PG4 (TOSC1)
19
PG3 (TOSC2)
18
ATMEGA128
U1
GND
VTG
GND
VTG
1
2
3
4
5
6
7
8
9
10
JTAG
J1
TCK
TDO
TMS
VCC
TDI
GND
Vref
NSRST
NTRST
GND
GND
GND
VTG
VTG
10k
R1
VTG
The JTAG connector is compatible with the 10-pin standard from Atmel.
Connection with the target circuit
The connection to the target circuit should be realized through the attached 10-lead ribbon cable,
terminated with standard IDC plugs with 2.54 mm raster. In case of using another cable it should be
kept in mind that it should not be longer than 30 cm (~12 inches). The target device should be
equipped with a JTAG connector with lead-out identical to that of the emulator JTAG connector. We
connect the JTAG bus lines with their corresponding JTAG bus lines of the microcontroller as shown
in the figure below.
Connection with the ATmega128 microcontroller
It is necessary to make a suitable adapter, when connecting the JTAGcable II emulator to a target
device having a JTAG connector in another standard.
Level converter of JTAG signals
In order to assure proper operation of the emulator when the supply voltages of the target circuit
differ from the emulator’s supply voltage, level converters of JTAG signals come into use. The
conversion circuits have been designed for operation with a target circuit supplied from a voltage
between 1.8 and 6 V.
The JTAGcable II can be supplied from an external source or directly from the target circuit. In the
last case, the supply voltage should have a value between 4.5 and 5.5 V.
Signals between the programmer and the target circuit can be divided into three groups: input
signals (TDO), output (TCK, TMS, TDI) and input/output (NSRST). Besides regenerating JTAG bus
