pnx1500 NXP Semiconductors, pnx1500 Datasheet - Page 750

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

Philips Semiconductors
Volume 1 of 1
3. Operation
PNX15XX_SER_3
Product data sheet
2.1.3 PNX15xx Series JTAG Instruction Set
3.1 Register Programming Guidelines
(loaded in parallel into the shift register stage), n bits are shifted in and
simultaneously, n bits are shifted out. Finally the register is “updated” with the new n
bits shifted in.
Note that when a register is scanned, its old value is shifted out of TDO and the new
value shifted in via TDI is written to the register at the Update state. Hence, scan in/
out involve the same steps. This also means that reading a register via JTAG destroys
its contents unless otherwise stated.
Some registers are specified as read-only via JTAG so that when the controller
transitions to the Update state for the read-only register, the update has no effect.
Some times, read/write registers are needed (e.g., control registers used for
handshake) which must be read non-destructively. In such cases, the value shifted in
determines whether the old value is “remembered” or something else happens.
PNX15xx Series uses a 5-bit JTAG instruction register. The unspecified opcodes are
private and their effects are undefined.
TM_DBG module.
Table 1: JTAG TM3260 Instruction Encoding
The standard JTAG instructions such as EXTEST, SAMPLE/PRELOAD, BYPASS and
IDCODE are implemented and listed in
Table 2: JTAG Instruction Encoding
Because the JTAG data registers live in MMIO space and are accessible by both the
TM3260 CPU and the JTAG controller at the same time, race conditions must not
exist either in hardware or in software. The communication protocol uses a
handshake mechanism to avoid software race conditions.
Encodin
g
10001
10010
10011
10100
10101
10110
Encoding
00000
00001
00010
11111
TM_DBG_SEL_DATA_IN
TM_DBG_SEL_DATA_OUT
TM_DBG_SEL_IFULL_IN
TM_DBG_SEL_OFULL_OUT
TM_DBG_SEL_TM_DBG_CTL1
TM_DBG_SEL_TM_DBG_CTL2
Instruction name
EXTEST
SAMPLE
ICODE
BYPASS
Instruction Name
Rev. 3 — 17 March 2006
Table 1
Table
Action
Select TM_DBG_DATA_IN register
Select TM_DBG_DATA_OUT register
Select TM_DBG_IFULL_IN register
Select TM_DBG_OFULL_OUT register
Select TM_DBG_CTRL register 1
Select TM_DBG_CTRL register 2
Action
Select boundary scan register
Select boundary scan register
Select Identification register
Select bypass register
2.
lists the JTAG instructions related to
© Koninklijke Philips Electronics N.V. 2006. All rights reserved.
Chapter 24: TM3260 Debug
PNX15xx Series
24-4