R01UH0823EJ0100 Rev.1.00
Page 1767 of 1823
Jul 31, 2019
RX23W Group
51. Electrical Characteristics
51.3
AC Characteristics
51.3.1
Clock Timing
Note 1. The lower-limit frequency of FCLK is 1 MHz during programming or erasing of the flash memory. When FCLK is in use at below
4 MHz, the frequency can be set to 1 MHz, 2 MHz, or 3 MHz. A non-integer frequency such as 1.5 MHz cannot be set.
Note 2. The frequency accuracy of FCLK must be within ±3.5%.
Note 3. The VCC_USB range is 3.0 to 3.6 V when the USB clock is in use.
Note 4. The maximum operating frequency listed above does not include errors of the external oscillator and internal oscillator. For
details on the range for the guaranteed operation, see Table 51.24, Clock Timing.
Note 1. The lower-limit frequency of FCLK is 1 MHz during programming or erasing of the flash memory. When using FCLK at below 4
MHz, the frequency can be set to 1 MHz, 2 MHz, or 3 MHz. A non-integer frequency such as 1.5 MHz cannot be set.
Note 2. The frequency accuracy of FCLK must be within ±3.5%.
Note 3. The VCC_USB range is 3.0 to 3.6 V when the USB clock is in use.
Note 4. The maximum operating frequency listed above does not include errors of the external oscillator and internal oscillator. For
details on the range for the guaranteed operation, see Table 51.24, Clock Timing.
Table 51.21
Operating Frequency Value (High-Speed Operating Mode)
Conditions: 1.8 V ≤ VCC = VCC_USB = AVCC0 = VCC_RF = AVCC_RF ≤ 3.6 V, VSS = AVSS0 = VSS_USB = VSS_RF = 0 V,
T
a
= –40 to +85°C
Item
Symbol
VCC
Unit
1.8 V ≤ VCC
< 2.4 V
2.4 V ≤ VCC
< 2.7 V
2.7 V ≤ VCC
≤ 3.6 V
When USB
is in Use*
Maximum
operating
frequency*
System clock (ICLK)
f
max
8
16
54
54
MHz
FlashIF clock (FCLK)*
8
16
32
32
Peripheral module clock (PCLKA)
8
16
54
54
Peripheral module clock (PCLKB)
8
16
32
32
Peripheral module clock (PCLKD)
8
32
54
54
USB clock (UCLK)
f
usb
—
—
—
48
Table 51.22
Operating Frequency Value (Middle-Speed Operating Mode)
Conditions: 1.8 V ≤ VCC = VCC_USB = AVCC0 = VCC_RF = AVCC_RF ≤ 3.6 V, VSS = AVSS0 = VSS_USB = VSS_RF = 0 V,
T
a
= –40 to +85°C
Item
Symbol
VCC
Unit
1.8 V ≤ VCC
< 2.4 V
2.4 V ≤ VCC
< 2.7 V
2.7 V ≤ VCC
≤ 3.6 V
When USB
is in Use*
Maximum
operating
frequency*
System clock (ICLK)
f
max
8
12
12
12
MHz
FlashIF clock (FCLK)*
8
12
12
12
Peripheral module clock (PCLKA)
8
12
12
12
Peripheral module clock (PCLKB)
8
12
12
12
Peripheral module clock (PCLKD)
8
12
12
12
USB clock (UCLK)
f
usb
—
—
—
48
