M3087BFLBGP#U5 Renesas Electronics America, M3087BFLBGP#U5 Datasheet - Page 128

• 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 104 of 587
9.6
Figure 9.16
The system clock protect function prohibits the clock setting from being rewritten in order to prevent the CPU
clock source from being changed when a program goes out of control.
When the PM21 bit in the PM2 register is set to 1 (disables a clock change), the following bits cannot be written:
The CPU clock continues running when the WAIT instruction is executed.
Figure 9.16 shows a procedure to use the system clock protect function. Follow the procedure while the CM05 bit
in the CM0 register is set to 0 (main clock oscillates) and the CM07 bit to 0 (main clock as CPU clock source).
NOTE:
•
•
•
•
Bits CM02, CM05, and CM07 in the CM0 register
Bits CM10 and CM17 in the CM1 register
The CM20 bit in the CM2 register
All bits in registers PLC0 and PLC1
1. When entering wait mode, execute the WAIT instruction while the PM21 bit in the PM2 register is set to 0.
System Clock Protect Function
PRCR register: PRC1 bit = 1
PM2 register: PM21 bit = 1
PRCR register: PRC1 bit = 0
Procedure to Use System Clock Protect Function
Start
End
(Note 1)
Enable writing to registers associated with clocks
Disable a clock change
Disable writing to registers associated with clocks
9. Clock Generation Circuits