DS3171N+ Maxim Integrated Products, DS3171N+ Datasheet - Page 213

• Manufacturer Part Number: DS3171N+
• Description: TXRX SGL DS3/E3 400PBGA
• Manufacturer: Maxim Integrated Products

Specifications of DS3171N+

• Function: Single-Chip Transceiver
• Interface: DS3, E3
• Number Of Circuits: 1
• Voltage - Supply: 3.135 V ~ 3.465 V
• Current - Supply: 273mA
• Operating Temperature: -40°C ~ 85°C
• Mounting Type: Surface Mount
• Package / Case: 400-BGA
• Includes: DS3 Framers, E3 Framers, HDLC Controller, On-Chip BERTs
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Power (watts): -
• Other names: 90-31710+N00

13.3 JTAG Instruction Register and Instructions
The instruction register contains a shift register as well as a latched parallel output and is 3 bits in length. When the
TAP controller enters the Shift-IR state, the instruction shift register is connected between JTDI and JTDO. While in
the Shift-IR state, a rising edge on JTCLK with JTMS low shifts data one stage toward the serial output at JTDO. A
rising edge on JTCLK in the Exit1-IR state or the Exit2-IR state with JTMS high moves the controller to the Update-
IR state. The falling edge of that same JTCLK latches the data in the instruction shift register to the instruction
parallel output. Instructions supported by the device and their respective operational binary codes are shown in
Table
Table 13-1. JTAG Instruction Codes
SAMPLE/PRELOAD. This is a mandatory instruction for the IEEE 1149.1 specification. This instruction supports
two functions. The digital I/Os of the device can be sampled at the boundary scan register without interfering with
the normal operation of the device and the boundary scan register can be pre-loaded for the EXTEST instruction.
The positive edge of JTCLK in the Capture-DR state samples all digital input pins into the boundary scan register.
The boundary scan register is connected between JTDI and JTDO. The data on JTDI pin is clocked into the
boundary scan register and the data captured in the Capture-DR state is shifted out the TDO pin in the Shift-DR
state.
EXTEST. This is a mandatory instruction for the IEEE 1149.1 specification. This instruction allows testing of all
interconnections to the device. When the EXTEST instruction is latched in the instruction register, the following
actions occur. Once enabled by the Update-IR state, the parallel outputs of all digital output pins are driven
according to the values in the boundary scan registers on the positive edge of JTCLK. The boundary scan register
is connected between JTDI and JTDO. The positive edge of JTCLK in the Capture-DR state samples all digital
input pins into the boundary scan register. The negative edge of JTCLK in the Update-DR state causes all of the
digital output pins to be driven according to the values in the boundary scan registers that have been shifted in
during the Shift-DR state. The outputs are returned to their normal mode or HIZ mode at the positive edge of
JTCLK during the Update-IR state when an instruction other than EXTEST or CLAMP is activated.
BYPASS. This is a mandatory instruction for the IEEE 1149.1 specification. When the BYPASS instruction is
latched into the parallel instruction register, JTDI connects to JTDO through the 1-bit bypass test register. This
allows data to pass from JTDI to JTDO not affecting the device’s normal operation. This mode can be used to
bypass one or more chips in a system with multiple chips that have their JTAG scan chain connected in series. The
chips not in bypass can then be tested with the normal JTAG modes.
IDCODE. This is a mandatory instruction for the IEEE 1149.1 specification. When the IDCODE instruction is
latched into the parallel instruction register, the identification test register is selected. The device identification code
is loaded into the identification register on the rising edge of JTCLK following entry into the Capture-DR state. Shift-
DR can be used to shift the identification code out serially through JTDO. During Test-Logic-Reset, the
identification code is forced into the instruction register’s parallel output.
HIGHZ. All digital outputs are placed into a high-impedance state. The bypass register is connected between JTDI
and JTDO. The outputs are put into the HIZ mode when the HIZ instruction is loaded in the Update-IR state and on
the positive edge of JTCLK. The outputs are returned to their normal mode or driven from the boundary scan
register at the positive edge of JTCLK during the Update-IR state when an instruction other than HIZ is activated.
SAMPLE/PRELOAD
INSTRUCTIONS
13-1.
BYPASS
EXTEST
IDCODE
CLAMP
HIGHZ
—
—
SELECTED REGISTER
Device Identification
Boundary Scan
Boundary Scan
Bypass
Bypass
Bypass
Bypass
Bypass
213
INSTRUCTION CODES
000
001
010
011
100
101
110
111