peb20525 Infineon Technologies Corporation, peb20525 Datasheet - Page 246

• Manufacturer Part Number: peb20525
• Description: 2 Channel Serial Optimized Communication Controller For Hdlc/ppp
• Manufacturer: Infineon Technologies Corporation

8
8.1
In the SEROCCO-H a Test Access Port (TAP) controller is implemented. The essential
part of the TAP is a finite state machine (16 states) controlling the different operational
modes of the boundary scan. Both, TAP controller and boundary scan, meet the
requirements given by the JTAG standard: IEEE 1149.1.
about the TAP controller.
Figure 80
If no boundary scan operation is planned TRST has to be connected with V
and TDI do not need to be connected since pull-up transistors ensure high input levels
in this case. Nevertheless it would be a good practice to put these unused inputs to
defined levels, using pull-up resistors.
Test handling (boundary scan operation) is performed via the pins TCK (Test Clock),
TMS (Test Mode Select), TDI (Test Data Input) and TDO (Test Data Output) when the
TAP controller is not in its reset state, i.e. TRST is connected to V
unconnected due to its internal pull-up. Test data at TDI are loaded with a 4-MHz clock
Data Sheet
TCK
TRST
TMS
TDI
TDO
Test Modes
JTAG Boundary Scan Interface
Block Diagram of Test Access Port and Boundary Scan Unit
CLOCK
Reset
Test
Control
Data in
Enable
Data out
Test Access Port (TAP)
- Finite State Machine
- Instruction Register (3 bit)
- Test Signal Generator
Clock Generation
TAP Controller
CLOCK
246
Figure 80
ID Data out
Control
Bus
SS Data
out
6
gives an overview
DD
SS
or it remains
PEB 20525
2
1
n
PEF 20525
Test Modes
. TMS, TCK
Pins
.
.
.
.
.
.
2000-09-14