Examining And Setting Data Registers - Mitsubishi Electric M32R Series User Manual

Mitsubishi 32-bit risc single-chip microcomputers

Table of Contents

19.4.4 Examining and Setting Data Registers

To inspect or set the data register, follow the procedure described below.

(1) To access the test access port (JTAG) for the first time, enter test reset (to initialize the test

circuit). Test reset can be entered by one of the following two methods:

• Pull JTRST pin input low

• Drive JTMS pin input high and enter JTCK for 5 cycles or more

(2) Set JTMS = low to go to "Run-Test/Idle" state. To continue the idle state, hold JTMS input

(3) Set JTMS = high to exit "Run-Test/Idle" state and perform IR path sequence. In IR path

sequence, specify the data register you want to inspect or set.

(4) Subsequently, perform DR path sequence. For the data register specified in IR path

sequence, enter setup data from the JTDI pin and read out reference data from the JTDO

(5) If after DR path sequence is completed you want to proceed and perform IR path sequence

or DR path sequence, enter JTMS = high to return to "Select-DR-Scan" state. If after a series

of IR and DR path sequence processing is completed you want to wait for the next

processing, enter JTMS = low to go to "Run-Test/Idle" state and retain the state.

19.4 Basic Operation of JTAG