ST20-GP6 View Datasheet(PDF) - STMicroelectronics

Part Name

Description

Manufacturer

ST20-GP6

GPS PROCESSOR

STMicroelectronics 

ST20-GP6

23 Test access port

The ST20-GP6 Test Access Port (TAP) conforms to IEEE standard 1149.1.

The TAP consists of five pins: TMS, TCK, TDI, TDO and notTRST.

The instruction register is 5 bits long, with no parity, and the pattern “00001” is loaded into the reg-

ister during the Capture-IR state.

There are four defined public instructions, see Table 23.1. All other instruction codes are reserved.

Instruction codea Instruction

Selected register

0 0 0 0 0 EXTEST

Boundary-Scan

0 0 0 1 0 IDCODE

Identification

0 0 0 1 1 SAMPLE/PRELOAD Boundary-Scan

1 1 1 1 1 BYPASS

Bypass

Table 23.1 Instruction codes

a. MSB ... LSB; LSB closest to TDO.

There are three test data registers; Bypass, Boundary-Scan and Identification. These registers

operate according to 1149.1. The Boundary-Scan register is not supported on the ST20-GP6.

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