HD6417320 RENESAS [Renesas Technology Corp], HD6417320 Datasheet - Page 148

• 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
(2)
The repeat start register (RS) holds the start address of a loop repeat module that is controlled by
the repeat function. This register can be accessed in DSP mode. At reset, the initial value of this
register is undefined. This register is not affected in the exception handling state.
(3)
The repeat end register (RE) holds the end address of a loop repeat module that is controlled by
the repeat function. This register can be accessed in DSP mode. At reset, this register is initialized
to 0. This register is not affected in the exception handling state.
(4)
The modulo register stores the modulo end address and modulo start address for modulo
addressing in upper and lower 16 bits. The upper and lower 16 bits of the modulo register are
referred to as the ME register and MS register, respectively. This register can be accessed in DSP
mode. At reset, the initial value of this register is undefined. This register is not affected in the
exception handling state.
The above registers can be accessed by the control register load instruction (LDC) and store
instruction (STC). Note that the LDC and STC instructions for the RS, RE, and MOD registers can
be used only in privileged DSP mode and user DSP mode. The LDC and STC instruction for the
SR register can be executed only when the MD bit is set to 1 or in user DSP mode. Note, however,
that the LDC and STC instructions can modify only the RC11 to RC0, RF1 to RF0, DMX, and
DMY bits in the SR, as described below.
• In user mode, if the LCD and STC instructions are used for the RS, an illegal instruction
• In privileged and privileged DSP modes, all SR bits can be modified.
• In user DSP mode, the SR can be read by the STC instruction.
• In user DSP mode, the LDC instruction can be issued to the SR but only the DSP extension
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REJ09B0033-0300
exception occurs.
bits can be modified.
Repeat Start Register (RS)
Repeat End Register (RE)
Modulo Register (MOD)