Mode 7: In this mode, the CKIO pin is an input, an external clock is input to this pin, and
undergoes waveform shaping, and also frequency multiplication according to the setting, by PLL
circuit 1 before being supplied to the chip. In modes 0 to 2, the system clock is generated from the
output of the chip’s CKIO pin. Consequently, if a large number of ICs are operating on the clock
cycle, the CKIO pin load will be large. This mode, however, assumes a comparatively large-scale
system. If a large number of ICs are operating on the clock cycle, a clock generator with a number
of low-skew clock outputs can be provided, so that the ICs can operate synchronously by
distributing the clocks to each one.
As PLL circuit 1 compensates for fluctuations in the CKIO pin load, this mode is suitable for
connection of synchronous DRAM.
Table 9.4 Available Combinations of Clock Mode and FRQCR Values
*
Clock
Mode FRQCR PLL1
Clock Rate Input Frequency
(I:B:P) Range
CKIO Frequency
Range
PLL2
0
H'0100 ON (× 1) ON (× 1) 1:1:1
H'0101 ON (× 1) ON (× 1) 1:1:1/2
H'0102 ON (× 1) ON (× 1) 1:1:1/4
H'0111 ON (× 2) ON (× 1) 2:1:1
H'0112 ON (× 2) ON (× 1) 2:1:1/2
H'0115 ON (× 2) ON (× 1) 1:1:1
H'0116 ON (× 2) ON (× 1) 1:1:1/2
H'0122 ON (× 4) ON (× 1) 4:1:1
H'0126 ON (× 4) ON (× 1) 2:1:1
H'012A ON (× 4) ON (× 1) 1:1:1
H'A100 ON (× 3) ON (× 1) 3:1:1
H'A101 ON (× 3) ON (× 1) 3:1:1/2
H'E100 ON (× 3) ON (× 1) 1:1:1
H'E101 ON (× 3) ON (× 1) 1:1:1/2
H'A111 ON (× 6) ON (× 1) 6:1:1
25 MHz to 33.34 MHz 25 MHz to 33.34 MHz
25 MHz to 66.67 MHz 25 MHz to 66.67 MHz
25 MHz to 66.67 MHz 25 MHz to 66.67 MHz
25 MHz to 33.34 MHz 25 MHz to 33.34 MHz
25 MHz to 66.67 MHz 25 MHz to 66.67 MHz
25 MHz to 33.34 MHz 25 MHz to 33.34 MHz
25 MHz to 66.67 MHz 25 MHz to 66.67 MHz
25 MHz to 33.34 MHz 25 MHz to 33.34 MHz
25 MHz to 33.34 MHz 25 MHz to 33.34 MHz
25 MHz to 33.34 MHz 25 MHz to 33.34 MHz
25 MHz to 33.34 MHz 25 MHz to 33.34 MHz
25 MHz to 66.67 MHz 25 MHz to 66.67 MHz
25 MHz to 33.34 MHz 25 MHz to 33.34 MHz
25 MHz to 66.67 MHz 25 MHz to 66.67 MHz
25 MHz to 33.34 MHz 25 MHz to 33.34 MHz
Rev. 5.00, 09/03, page 208 of 760
RENESAS [ RENESAS TECHNOLOGY CORP ]
