TPCE261 User Manual Issue 1.0.2
Page 13 of 20
6 JTAG
There is one JTAG chain present on the TPCE261. This chain connects the 14-pin JTAG header with the
PMC slot. There are no JTAG-capable devices onboard the TPCE261, so the PMC is the only “device” in this
chain.
TDI and TDO of the PCIe connector will be interconnected on-board to maintain system board JTAG-Chain
integrity.
USB Type C Connector
The TPCE261 offers an USB Type C Receptacle as an alternative to the 14-pin flat cable header. This USB
receptacle is connected to an FTDI FT2232H chip that translates the USB signals to JTAG signals, allowing
access to the PMC JTAG chain with a second source programming software and a simple USB cable.
This USB connector is not mounted in any order options by default. Please contact TEWS if you are
interested in using it.
JTAG voltage for PMC Module
The JTAG signaling voltage level on the 14-pin header is always 3.3V.
However, the JTAG voltage that is used for the PMC module, can be setup by a rotary selector switch on the
TPCE261; it will be translated to the 3.3V on the JTAG connector.
Position
PMC JTAG Voltage
0
+1.5V
1
+1.8V
2
+2.5V
3
+3.3V
Table 6-1 : Rotary Selector Switch configuration
Figure 6-1 : JTAG voltage rotary selector switch location (Top View of TPCE261)
