pnx1500 NXP Semiconductors, pnx1500 Datasheet - Page 748

• Manufacturer Part Number: pnx1500
• Description: Pnx15xx Series Connected Media Processor
• Manufacturer: NXP Semiconductors

Philips Semiconductors
Volume 1 of 1
PNX15XX_SER_3
Product data sheet
2.1.2 TAP Controller
TDO is the serial output for test instructions and data from the TAP controller.
Changes in the state of TDO must occur at the falling edge of TCK. This is because
devices connected to TDO are required to sample TDO at the rising edge of TCK.
The TDO driver must be in an inactive state (i.e., TDO line HIghZ) except when the
scanning of data is in progress.
The TAP controller is a finite state machine that synchronously responds to changes
in TCK and TMS signals. The TAP instructions and data are serially scanned into the
TAP controller’s instruction and data registers via the common input line TDI. The
TMS signal tells the TAP controller to select either the TAP instruction register or a
TAP data registers as the destination for serial input from the common line TDI. An
instruction scanned into the instruction register selects a data register to be
connected between TDI and TDO to become the destination for serial data input.
The TAP controller’s state changes are determined by the TMS signal. The states are
used for scanning in/out TAP instruction and data, updating instruction, and data
registers, and for executing instructions.
Rev. 3 — 17 March 2006
© Koninklijke Philips Electronics N.V. 2006. All rights reserved.
Chapter 24: TM3260 Debug
PNX15xx Series
24-2