DS3112
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11 JTAG
The DS3112 device supports the standard instruction codes SAMPLE/PRELOAD, BYPASS, and
EXTEST. Optional public instructions included are HIGHZ, CLAMP, IDCODE (
DS3112 contains the following items that meet the requirements set by the IEEE 1149.1 Standard Test
Access Port and Boundary Scan Architecture:
Test Access Port (TAP)
TAP Controller
Instruction Register
Bypass Register
Boundary Scan Register
Device Identification Register
The Test Access Port has the necessary interface pins, namely JTCLK,
JTRST
, JTDI, JTDO, and JTMS.
Details on these pins can be found in Section
. Details on the Boundary Scan Architecture and the Test
Access Port can be found in IEEE 1149.1-1990, IEEE 1149.1a-1993, and IEEE 1149.1b-1994.
Figure 11-1. JTAG Block Diagram
Boundary Scan
Register
Identification
Register
Bypass
Register
Instruction
Register
Test Access Port
Controller
Mux
Select
Tri-State
JTDI
10K
JTMS
10K
JTCLK
JTRST
10K
JTDO