79RC32H434-300BC IDT, 79RC32H434-300BC Datasheet - Page 33

• Manufacturer Part Number: 79RC32H434-300BC
• Description: Processors - Application Specialized
• Manufacturer: IDT

Specifications of 79RC32H434-300BC

• Part # Aliases: IDT79RC32H434-300BC

a boundary scan or a probe. Reset can occur through a pull-down resistor on JTAG_TRST_N if the probe is not connected. However, on-chip pull-up
resistors are implemented on the RC32434 due to an IEEE 1149.1 requirement. Having on-chip pull-up and external pull-down resistors for the
JTAG_TRST_N signal requires special care in the design to ensure that a valid logical level is provided to JTAG_TRST_N, such as using a small
external pull-down resistor to ensure this level overrides the on-chip pull-up. An alternative is to use an active power-up reset circuit for
JTAG_TRST_N, which drives JTAG_TRST_N low only at power-up and then holds JTAG_TRST_N high afterwards with a pull-up resistor.
IDT RC32434
The IEEE 1149.1 specification requires that the JTAG and EJTAG TAP controllers be reset at power-up whether or not the interfaces are used for
Figure 20 shows the electrical connection of the EJTAG probe target system connector.
Other reset
sources
JTAG_TRST_N
EJTAG_TMS
JTAG_TMS
JTAG_TDO
JTAG_TCK
JTAG_TDI
Target System
Reset (soft/hard)
Reset Circuit
RC32434
JTAG_TRST_N
EJTAG_TMS
JTAG_TDO
JTAG_TCK
JTAG_TDI
Figure 20 Target System Electrical EJTAG Connection
Tpw_16d
Tpw_16d
Figure 19 JTAG AC Timing Waveform
VDD
Tsu_16e
Tsu_16b
Tsu_16b
Thld_16b
Thld_16b
Thld_16e
Thigh_16a
Series-res.
33 of 53
GND
Tlow_16a
Tlow_16a
Tdo_16c
no connect
TRST*
RST*
DINT
TDO
TMS
TCK
Tper_16a
TDI
1
VccIO voltage
GND
GND
GND
GND
GND
VccIO
reference
Tdz_16c
GND
January 19, 2006