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Jtag functional timing, Io pins, Jtag f – Rainbow Electronics DS3170 User Manual

Page 207: Unctional, Iming, Io p, Figure 12-3. jtag functional timing, 5 jtag functional timing, 6 io pins

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DS3170 DS3/E3 Single-Chip Transceiver

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12.5 JTAG Functional Timing

This functional timing for the JTAG circuits shows:

· The JTAG controller starting from reset state
· Shifting out the first 4 LSB bits of the IDCODE
· Shifting in the BYPASS instruction (111) while shifting out the mandatory X01 pattern
· Shifting the TDI pin to the TDO pin through the bypass shift register
· An asynchronous reset occurs while shifting

Figure 12-3. JTAG Functional Timing

JTCLK

JTRST

JTMS

JTDI

JTDO

(STATE)

Reset

X

Run Test

Idle

Select DR

Scan

Capture

DR

Shift

DR

Exit1

DR

Update

DR

Select DR

Scan

Select IR

Scan

Capture

IR

Shift IR

Exit1

IR

Update

IR

Select DR

Scan

Capture

DR

Shift

DR

Test

Logic Idle

(INST)

IDCODE

BYPASS

IDCODE

X

X

X

X

X

Output

Pin

Output pin level change if in "EXTEST" instruction mode

12.6 IO Pins

All input, output, and inout pins are inout pins in JTAG mode.