M3087BFLBGP#U5 Renesas Electronics America, M3087BFLBGP#U5 Datasheet - Page 114

• Manufacturer Part Number: M3087BFLBGP#U5
• Description: IC M32C/87 MCU FLASH 144LQFP
• Manufacturer: Renesas Electronics America
• Series: M16C™ M32C/80r

Specifications of M3087BFLBGP#U5

• Core Processor: M32C/80
• Core Size: 16/32-Bit
• Speed: 32MHz
• Connectivity: EBI/EMI, I²C, IEBus, IrDA, SIO, UART/USART
• Peripherals: DMA, POR, PWM, WDT
• Number Of I /o: 121
• Program Memory Size: 1MB (1M x 8)
• Program Memory Type: FLASH
• Ram Size: 48K x 8
• Voltage - Supply (vcc/vdd): 3 V ~ 5.5 V
• Data Converters: A/D 34x10b, D/A 2x8b
• Oscillator Type: Internal
• Operating Temperature: -20°C ~ 85°C
• Package / Case: 144-LQFP
• For Use With: R0K330879S001BE - KIT DEV RSK M32C/87R0K330879S000BE - KIT DEV RSK M32C/87
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Eeprom Size: -

M32C/87 Group (M32C/87, M32C/87A, M32C/87B)
REJ09B0180-0151 Rev.1.51 Jul 31, 2008
Page 90 of 587
Figure 9.10
9.1.2
(On-chip feedback resistor)
Sub clock oscillation circuit generates the sub clock. The sub clock is used as the clock source for the CPU
clock and for timer A and timer B. fC, which has the same frequency as the sub clock can be output from the
CLKOUT pin.
The sub clock oscillation circuit is configured by connecting a crystal oscillator between the XCIN and
XCOUT pins. The circuit has an on-chip feedback resistor. The feedback resistor is disconnected from the
oscillation circuit in stop mode to reduce power consumption. The sub clock oscillation circuit may also be
configured by feeding an externally generated clock to the XCIN pin. Figure 9.10 shows an example of sub
clock circuit connection. Circuit constants vary depending on each oscillator. Use the circuit constant
recommended by each oscillator manufacturer.
The sub clock is stopped after reset, and the feedback resistor is disconnected from the oscillation circuit. To
start oscillating the sub clock oscillation circuit, set both the PD8_7 and PD8_6 bits in the PD8 register to 0
(input mode), the PU25 bit in the PUR2 register to 0 (not pulled up), and then the CM04 bit in the CM0 register
to 1 (XCIN-XCOUT oscillation function). To input the externally generated clock to the XCIN pin, set the
PD8_7 bit to 0, the PU25 bit to 0, and then the CM04 bit to 1. A clock input to the XCIN pin becomes the clock
source for the sub clock.
When the CM07 bit in the CM0 register is set to 1 (sub clock) after the sub clock oscillation stabilizes, the sub
clock becomes the CPU clock source.
All clocks, including the sub clock, stop in stop mode. Refer to 9.5 Power Consumption Control for details.
NOTE:
1. Insert a damping resistor if required. Resistance values vary depending on the oscillator setting. Use the resistance values
If the oscillator manufacturer recommends that a feedback resistor be added to the chip externally, insert a feedback
MCU
recommended by the oscillator manufacturer.
resistor between XCIN and XCOUT following the instructions.
Sub Clock
XCOUT
Sub Clock Circuit Connection
XCIN
VSS
Oscillator
RCd
(1)
CCOUT
CCIN
(On-chip feedback resistor)
MCU
XCOUT
XCIN
Open
VCC
VSS
Externally generated clock
9. Clock Generation Circuits