SH7205 Datasheet, PDF (150/1904 Pages) Renesas Technology Corp – Renesas 32-Bit RISC Microcomputer SuperHTM RISC engine Family / SH7200 Series

Section 5 Clock Pulse Generator (CPG)
5.3 Clock Operating Modes
Table 5.2 shows the relationship between the combinations of the mode control pins (MD_CLK1
and MD_CLK0) and the clock operating modes. Table 5.3 shows the usable frequency ranges in
clock operating modes.
Table 5.2 Clock Operating Modes
Pin Values
Mode MD_CLK1 MD_CLK0
00
0
10
1
21
0
31
1
Clock I/O
PLL Circuit
Source
Output Divider 1 On/Off
EXTAL or crystal CKIO 1
resonator
ON (12, 16)
EXTAL or crystal CKIO 1/2
resonator
ON (12, 16)
CKIO

1/4
ON (12, 16)
USB_X1 or
CKIO 1/4
crystal resonator
ON (12, 16)
CKIO Frequency
(EXTAL or crystal
resonator) × 4
(EXTAL or crystal
resonator) × 2
(CKIO)
(USB_X1 or
crystal resonator)
• Mode 0
In mode 0, a clock is input from the EXTAL pin or the crystal oscillator. The PLL circuit
shapes waveforms and the frequency is multiplied according to the frequency control register
setting before the clock is supplied to the LSI. The oscillating frequency for the crystal
resonator and EXTAL pin input clock ranges from 10 to 16.67 MHz. The frequency range of
CKIO is from 40 to 66.66 MHz. The internal clock frequency is the EXTAL pin frequency
multiplied by the frequency multiplication rate of the PLL circuit and the division ratio of the
divider 2. To reduce current, pull up the USB_X1 pin and open the USB_X2 pin when USB is
not used.
• Mode 1
In mode 1, a clock is input from the EXTAL pin or the crystal oscillator. The PLL circuit
shapes waveforms and the frequency is multiplied according to the frequency control register
setting before the clock is supplied to the LSI. The oscillating frequency for the crystal
resonator and EXTAL pin input clock ranges from 20 to 33.33 MHz. The frequency range of
CKIO is from 40 to 66.66 MHz. The internal clock frequency is half the EXTAL pin frequency
multiplied by the frequency multiplication rate of the PLL circuit and the division ratio of the
divider 2. To reduce current, pull up the USB_X1 pin and open the USB_X2 pin when USB is
not used.
Rev. 1.00 Mar. 25, 2008 Page 118 of 1868
REJ09B0372-0100