Datasheet

Table Of Contents
Section 14 Boundary Scan Function
Page 474 of 846 REJ09B0140-0900 Rev. 9.00
Sep 16, 2010
H8S/2215 Group
14.3 Register Descriptions
The boundary scan function has the following registers. These registers cannot be accessed by the
CPU.
Instruction register (INSTR)
IDCODE register (IDCODE)
BYPASS register (BYPASS)
Boundary scan register (BSCANR)
14.3.1 Instruction Register (INSTR)
INSTR is a 3-bit register. At initialization, this register is specified to IDCODE mode. When
TRST is pulled low, or when the TAP controller is in the Test-Logic-Reset state, INSTR is
initialized. INSTR can be written by the serial data input from the TDI. If more than three bits of
instruction is input from the TDI, INSTR stores the last three bits of serial data.
If a command reserved in INSTR is used, the correct operation cannot be guaranteed.
Bit Bit Name Initial Value R/W Description
2 TI2 1
1 TI1 0
Test Instruction Bits
Instruction configuration is shown in table 14.2.
0 TI0 1
Table 14.2 Instruction configuration
Bit 2 Bit1 Bit 0
TI2 TI1 TI0 Instruction
0 0 0 EXTEST
0 0 1 SAMPLE/PRELOAD
0 1 0 CLAMP
0 1 1 HIGHZ
1 0 0 Reserved
1 0 1 IDCODE (initial value)
1 1 0 Reserved
1 1 1 BYPASS