ETAS
Hardware Description
XETK-S21.0B
-
User
Guide
24
4.9
JTAG Interface
Fig.
4
-
7
Equivalent Circuitry of the ECU JTAG Interface (ECU)
The ECU part of the JTAG XETK interface is depicted in Fig.
The XETK-S21.0 incorporates 22 Ohm series resistors for the TMS, TCK, TDI
and /TRST lines on the ECU interface. Hence, no additional termination resis
-
tors are required on the ECU for these signals.
Additionally, if a pull down resistor is present on the line /TRST, the ECU must
use a value no smaller than 10K ohm as shown in Fig.
24.
XETK
ETAI10
ETAI5 or ETAI6 or
ETAI8
/TRST
TMS
/PORST
>
=10k
Ubatt
GND
CAL WAKEUP
(12V)
VDDPSTBY
(1,25V) (I/O)
TDO
/TRST
/WGDIS
TCK
TDI
TDO
GND
TMS
/PORST
VDDP
(Sense)
/RSTOUT
TCK
ESR0
1
2
9
10
VD
D
SR
A
M
TDI
1. XETK: supply
and
monitor
the voltage of the ED RAM
R
XE
TK
=
0
R
EC
U
=
0
2. ECU: supply
the voltage of the ED RAM
OR
permanent power supply
VDDPSTBY
sense (I)
2.XETK: monitor
the voltage of the ED RAM
Power supply of the ED RAM:
Option 1: provided by XETK
Option 2: provided by ECU
ECU
JDP
57xx
/WGDIS circuit
