HD6417320 RENESAS [Renesas Technology Corp], HD6417320 Datasheet - Page 164

• Manufacturer Part Number: HD6417320
• Description: Renesas 32-Bit RISC Microcomputer SuperHTM RISC engine Family / SH7700 Series
• Manufacturer: RENESAS [Renesas Technology Corp]

Section 3 DSP Operating Unit
Double data transfer instructions can be described in parallel to the DSP operation instructions.
Even if a conditional operation instruction is specified in parallel to a double data transfer
instruction, the specified condition does not affect the data transfer operations. For details, refer to
section 3.5, DSP Data Operation Instructions.
Double data transfer instructions can access only the X memory or Y memory and cannot access
other memory space. The X bus and Y bus are 16 bits and support 64-byte address spaces
corresponding to address areas H'A5000000 to H'A500FFFF and H'A5010000 to H'A501FFFF,
respectively. Because these areas are included in the P2/Uxy area, they are not affected by the
cache and address translation unit.
(2) Single data transfer instructions
The single data transfer instructions access any memory location. All DSP registers other than the
DSR can be specified as source and destination operands.* Guard bit registers A0G and A1G can
also be specified as two independent registers. Because these instructions use the L bus (LAB and
LDB), these instructions can access any virtual space handled by the CPU. If these instructions
access the cacheable area while the cache is enabled, the area accessed by these instructions are
cached. The X memory and Y memory are mapped to the virtual address space and can also be
accessed by the single data transfer instructions. In this case, bus conflict may occur between data
transfer and instruction fetch because the CPU also uses the L bus for instruction fetches.
The single data transfer instructions can handle both word and longword data. In word data
transfer, only the upper word of the operand register is valid. In word data load, word data is
loaded into the upper word of the destination registers and the lower word of the destination is
automatically cleared to 0. If the guard bits are supported, the sign bit is extended before storage.
In longword data load, longword data is loaded into the upper and lower word of the destination
register. If the guard bits are supported, the sign bit is extended before storage. When the guard
register is stored, the sign bit is extended to the upper 24 bits of the LDB and are loaded onto the
LDB bus.
Notes: * Since the DSR register is defined as the system register, it can be accessed by the LDS
Rev. 3.00 Jan. 18, 2008 Page 102 of 1458
REJ09B0033-0300
1. Any data transfer instruction is executed at the MA stage of the pipeline.
2. Any data transfer instruction does not modify the condition code bits of the DSR
or STS instruction.
register.