HD6417705F133V Datasheet, PDF (321/741 Pages) Renesas Technology Corp – Renesas 32-Bit RISC Microcomputer SuperH RISC engine Family/SH7700 Series

The clock pulse generator blocks function as follows:
1. PLL Circuit 1
PLL circuit 1 doubles, triples, quadruples, or leaves unchanged the input clock frequency from
the CKIO pin or PLL circuit 2. The multiplication rate is set by the frequency control register.
When this is done, the phase of the rising edge of the internal clock is controlled so that it will
synchronize with the phase of the rising edge of the CKIO pin.
2. PLL Circuit 2
PLL circuit 2 leaves unchanged, doubles, or quadruples the input clock frequency coming from
the crystal oscillator or EXTAL pin. The multiplication ratio is fixed by the clock-operating
mode. The clock-operating mode is set by pins MD0, MD1, and MD2. For more details on
clock operating modes, refer to table 9.2.
3. Crystal Oscillator
This oscillator circuit is used when a crystal resonator is connected to the XTAL and EXTAL
pins. This crystal oscillator operates according to the clock operating mode setting.
4. Divider 1
Divider 1 generates a clock at the operating frequency used by the internal or peripheral clock.
The operating frequency can be 1, 1/2, 1/3, or 1/4 times the output frequency of PLL circuit 1,
as long as it stays at or above the clock frequency of the CKIO pin. The division ratio is set in
the frequency control register.
5. Clock Frequency Control Circuit
The clock frequency control circuit controls the clock frequency using the MD0, MD1, and
MD2 pins and the frequency control register.
6. Standby Control Circuit
The standby control circuit controls the state of the on-chip oscillator and other modules during
clock switching and software/standby modes.
7. Frequency Control Register
The frequency control register has control bits assigned for the following functions: clock
output/non-output from the CKIO pin, the frequency multiplication ratio of PLL circuit 1, and
the frequency division ratio of the internal clock and the peripheral clock.
8. Standby Control Register
The standby control register has bits for controlling the power-down modes. See section 11,
Power-Down Modes, for more information.
9. USB Clock Control Register
The source clock generating the USB clock is set in the USB clock control register.
Rev. 2.00, 09/03, page 273 of 690