ds2156gn Maxim Integrated Products, Inc., ds2156gn Datasheet - Page 225

• Manufacturer Part Number: ds2156gn
• Description: Ds2156, Ds2156l, Ds2156ln T1/e1/j1 Single-chip Transceiver Tdm/utopia Ii Interface
• Manufacturer: Maxim Integrated Products, Inc.

33.
33.1 Description
The DS2156 IEEE 1149.1 design supports the standard instruction codes SAMPLE/PRELOAD,
BYPASS, and EXTEST. Optional public instructions included are HIGH-Z, CLAMP, and IDCODE
(Figure 33-1.). The DS2156 contains the following features as required by IEEE 1149.1 standard test
access port (TAP) and boundary scan architecture.
The DS2156 is pin-compatible with the DS2152, DS21x52 (T1) and DS2154, DS21x54 (E1) SCT
families. The JTAG feature uses pins that had no function in the DS2152 and DS2154. Details about
boundary scan architecture and the TAP are in IEEE 1149.1-1990, IEEE 1149.1a-1993, and IEEE
1149.1b-1994.
The TAP contains the necessary interface pins JTRST, JTCLK, JTMS, JTDI, and JTDO. See the pin
descriptions in Section 3 for details.
Figure 33-1. JTAG Functional Block Diagram
Test Access Port
TAP Controller
Instruction Register
Bypass Register
Boundary Scan Register
Device Identification Register
JTAG BOUNDARY SCAN ARCHITECTURE AND TEST ACCESS PORT
10kΩ
+V
JTDI
10kΩ
+V
JTMS
TEST ACCESS PORT
BOUNDARY SCAN
IDENTIFICATION
CONTROLLER
INSTRUCTION
REGISTER
REGISTER
REGISTER
REGISTER
BYPASS
JTCLK
225 of 265
10kΩ
+V
JTRST
SELECT
OUTPUT ENABLE
MUX
JTDO