RX610 Group
7. Clock Generation Circuit
R01UH0032EJ0120 Rev.1.20
Page 166 of 1006
Feb 20, 2013
7.6
Internal Clock
The internal clock is generated by multiplying the external input clock (EXTAL) by 8 with the PLL circuit, and then by
dividing the multiplied clock by 1, 2, 4, or 8 with the frequency divider.
There are following three types of internal clock.
•
Operating clock of the CPU, DMAC, and DTC: System clock (ICLK)
•
Operating clock of peripheral modules: Peripheral module clock (PCLK)
•
Clock for the external bus controller and external pin output: External bus clock (BCLK)
The frequencies are set by bits ICK[3:0], PCK[3:0], and BCK[3:0] in SCKCR, respectively.
7.6.1
System Clock (ICLK)
The system clock (ICLK) is used as the operating clock of the CPU, DMAC, DTC, ROM, and RAM.
The ICLK frequency is specified by the ICK[3:0] bits in SCKCR.
A frequency lower than the peripheral module clock (PCLK) and external bus clock (BCLK) should not be set for the
ICLK. If such a frequency is set, the frequency of ICLS will be the same as that of the PCLK or BCLK.
7.6.2
Peripheral Module Clock (PCLK)
The peripheral module clock (PCLK) is the operating clock for peripheral modules.
The PCLK frequency is specified by the PCK[3:0] bits in SCKCR.
A frequency higher than the system clock (ICLK) should not be set for the PCLK. If such a frequency is set, the clock
frequency will be the same as the ICLK.
7.6.3
External Bus Clock (BCLK)
The external bus clock (BCLK) is output on an external pin as the clock signal for the external connection bus.
Setting the PSTOP1 bit in SCKCR to 0 and the B3 bit in DDR for port 5 (P5.DDR) to 1 selects output of the BCLK on
the BCLK output pin. However, note that the order of setting for these bits requires care. Specifically, change the value
of the B3 bit in P5.DDR while the value of the PSTOP1 bit in SCKCR is 1.
The BCLK frequency is specified by the BCK[3:0] bits in SCKCR.
A frequency higher than the system clock (ICLK) should not be set for the BCLK. If such a frequency is set, the clock
frequency will be the same as the ICLK.
Summary of Contents for RX600 Series
Page 1006: ...RX610 Group R01UH0032EJ0120 ...