HD6417615 Hitachi Semiconductor, HD6417615 Datasheet - Page 731

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

17.3.3
The data register (SDDR) comprises data register H (SDDRH) and data register L (SDDRL), each
of which has the following configuration.
SDDRH and SDDRL are 16-bit registers that can be read and written to by the CPU. SDDR is
connected to TDO and TDI for serial data transfer to and from an external device.
32-bit data is input and output in serial data transfer. If data exceeding 32 bits is input, only the
last 32 bits will be stored in SDDR. Serial data is input starting from the MSB of SDDR (bit 15 of
SDDRH), and output starting from the LSB (bit 0 of SDDRL).
This register is not initialized by a reset, in standby mode, or by the TRST signal.
17.3.4
The bypass register (SDBPR) is a one-bit shift register. In bypass mode, SDBPR is connected to
TDI and TDO, and the chip is excluded from the board test when a boundary scan test is
conducted. SDBPR cannot be read or written to by the CPU.
17.3.5
The boundary scan register (SDBSR), a shift register that controls the I/O terminals of this LSI, is
provided on the PAD.
Using the EXTEST mode or the SAMPLE/PRELOAD mode, a boundary scan test conforming to
the IEEE1149.1 standard can be performed.
For SDBSR, read/write by the CPU cannot be performed.
Table 17.5 shows the relationship between the terminals of the LSI and the boundary scan register.
720
Initial value:
Initial value:
Data Register (SDDR)
Bypass Register (SDBPR)
Boundary scan register (SDBSR)
R/W:
R/W:
Bit:
Bit:
R/W
R/W
15
—
—
7
R/W
R/W
14
—
—
6
R/W
R/W
13
—
—
5
R/W
R/W
12
—
—
4
R/W
R/W
11
—
—
3
R/W
R/W
10
—
—
2
R/W
R/W
—
—
9
1
R/W
R/W
—
—
8
0