M306N5FCTFP Renesas Electronics America, M306N5FCTFP Datasheet - Page 90

• Manufacturer Part Number: M306N5FCTFP
• Description: IC M16C MCU FLASH 100QFP
• Manufacturer: Renesas Electronics America
• Series: M16C™ M16C/6Nr

Specifications of M306N5FCTFP

• Core Processor: M16C/60
• Core Size: 16-Bit
• Speed: 20MHz
• Connectivity: CAN, I²C, IEBus, SIO, UART/USART
• Peripherals: DMA, WDT
• Number Of I /o: 87
• Program Memory Size: 128KB (128K x 8)
• Program Memory Type: FLASH
• Ram Size: 5K x 8
• Voltage - Supply (vcc/vdd): 4.2 V ~ 5.5 V
• Data Converters: A/D 26x10b; D/A 2x8b
• Oscillator Type: Internal
• Operating Temperature: -40°C ~ 85°C
• Package / Case: 100-QFP
• Lead Free Status / RoHS Status: Contains lead / RoHS non-compliant
• Eeprom Size: -

M16C/6N Group (M16C/6N5)
Rev.2.40
REJ09B0011-0240
Figure 8.14 Procedure to Switch Clock Source from On-chip Oscillator to Main Clock
8.5.3 How to Use Oscillation Stop and Re-oscillation Detection Function
• The oscillation stop, re-oscillation detection interrupt shares the vector with the watchdog timer interrupt.
• Where the main clock re-oscillated after oscillation stop, the clock source for the CPU clock and peripheral
• Simultaneously with oscillation stop, re-oscillation detection interrupt request occurrence, the CM22 bit
• If the main clock stops during low speed mode where the CM20 bit is 1, an oscillation stop, re-oscillation
• To enter wait mode while using the oscillation stop and re-oscillation detection function, set the CM02
• Since the oscillation stop and re-oscillation detection function is provided in preparation for main clock
• This function cannot be used if the main clock frequency is 2 MHz or less. In that case, set the CM20 bit to 0.
If the oscillation stop, re-oscillation detection and watchdog timer interrupts both are used, read the
CM22 bit in an interrupt routine to determine which interrupt source is requesting the interrupt.
function must be switched to the main clock in the program. Figure 8.14 shows the Procedure to Switch
Clock Source from On-chip Oscillator to Main Clock.
becomes 1. When the CM22 bit is set at 1, oscillation stop, re-oscillation detection interrupt are disabled.
By setting the CM22 bit to 0 in the program, oscillation stop, re-oscillation detection interrupt are
enabled.
detection interrupt request is generated. At the same time, the on-chip oscillator starts oscillating. In this
case, although the CPU clock is derived from the sub clock as it was before the interrupt occurred, the
peripheral function clocks now are derived from the on-chip oscillator clock.
bit to 0 (peripheral function clocks not turned off during wait mode).
stop due to external sources, set the CM20 bit to 0 (oscillation stop, re-oscillation detection function
disabled) where the main clock is stopped or oscillated in the program, that is where the stop mode is
selected or the CM05 bit is altered.
Apr 14, 2006
page 68 of 372
NO
CM06 bit
Bits CM21, CM22, CM 23: Bits in CM2 register
NOTE:
1. If the clock source for CPU clock is to be changed to PLL clock,
set to PLL operating mode after set to high-speed mode.
Set the CM22 bit to 0 (main clock stop,
or PLL clock as CPU clock source)
Set the CM06 bit to 1 (divide-by-8)
Set the CM21 bit to 0 (main clock
whether the CM23 bit is set to 0
re-oscillation not detected)
Determine several times
(main clock oscillates)
Switch the main clock
End
: Bit in CM0 register
YES
(1)
8. Clock Generation Circuit