HD6417615 Hitachi Semiconductor, HD6417615 Datasheet - Page 728

• Manufacturer Part Number: HD6417615
• Description: Hardware Manual
• Manufacturer: Hitachi Semiconductor

17.2.5
The test reset pin (TRST) initializes the H-UDI asynchronously. If no signal is input, TRST is
fixed at 1 by internal pull-up.
17.3
17.3.1
The instruction register (SDIR) is a 16-bit register that can only be read by the CPU. H-UDI
instructions can be transferred to SDIR by serial input from TDI. SDIR can be initialized by the
TRST signal, but is not initialized by a reset or in standby mode.
Instructions transferred to SDIR must be 4 bits in length. If an instruction exceeding 4 bits is input,
the last 4 bits of the serial data will be stored in SDIR.
Operation is not guaranteed if a reserved instruction is set in this register.
Bits 15 to 12—Test Set Bits (TS3–TS0): Table 17.4 shows the instruction configuration.
Initial value:
Initial value:
Test Reset (TRST)
Register Descriptions
Instruction Register (SDIR)
R/W:
R/W:
Bit:
Bit:
TS3
15
—
1
R
7
0
R
TS2
14
—
1
R
6
0
R
TS1
13
—
1
R
5
0
R
TS0
12
—
0
R
4
0
R
11
—
—
0
R
3
0
R
10
—
—
0
R
2
0
R
—
—
9
0
R
1
0
R
—
—
8
0
R
0
0
R
717