R5F21162SP#U0 Renesas Electronics America, R5F21162SP#U0 Datasheet - Page 68

• Manufacturer Part Number: R5F21162SP#U0
• Description: IC R8C MCU FLASH 8K 20SSOP
• Manufacturer: Renesas Electronics America
• Series: M16C™ M16C/R8C/Tiny/16r

Specifications of R5F21162SP#U0

• Core Processor: R8C
• Core Size: 16-Bit
• Speed: 20MHz
• Connectivity: I²C, SIO, UART/USART
• Peripherals: LED, POR, Voltage Detect, WDT
• Number Of I /o: 13
• Program Memory Size: 8KB (8K x 8)
• Program Memory Type: FLASH
• Ram Size: 512 x 8
• Voltage - Supply (vcc/vdd): 2.7 V ~ 5.5 V
• Data Converters: A/D 4x10b
• Oscillator Type: Internal
• Operating Temperature: -20°C ~ 85°C
• Package / Case: 20-SSOP
• For Use With: R0K521134S000BE - KIT EVAL STARTER FOR R8C/13
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Eeprom Size: -

R8C/16 Group, R8C/17 Group
Rev.2.10
REJ09B0169-0210
9.5
Table 9.5
9.5.1
Oscillation Stop Detection Enable Clock
and Frequency Bandwidth
Oscillation Stop Detection Function
Enable Condition
Operation at Oscillation Stop Detection
The oscillation stop detection function is a function to detect the stop of the main clock oscillation circuit.
The oscillation stop detection function can be enabled or disabled by the OCD1 to OCD0 bits in the
OCD register.
Table 9.5 lists the Specification of Oscillation Stop Detection Function.
When the main clock is the CPU clock source and the OCD1 to OCD0 bits are set to “11b” (oscillation
stop detection function enabled), the system is placed in the following state if the main clock stops.
Oscillation Stop Detection Function
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Jan 19, 2006
OCD2 bit in OCD register = 1 (on-chip oscillator clock selected)
OCD3 bit in OCD register = 1 (main clock stops)
CM14 bit in CM1 register = 0 (low-speed on-chip oscillator oscillates)
Oscillation stop detection interrupt request is generated
The oscillation stop detection interrupt shares the vector with the voltage monitor 2 interrupt and
the watchdog timer interrupt. When using the oscillation stop detection interrupt and watchdog
timer interrupt, the interrupt factor needs to be determined. Table 9.6 lists the Determine Interrupt
Factor of Oscillation Stop Detection, Watchdog Timer and Voltage Monitor 2 Interrupts.
When the main clock is re-oscillated after the oscillation stops, switch the main clock to the clock
source of the CPU clock and peripheral functions by a program.
Figure 9.9 shows the Procedure of Switching Clock Source From Low-Speed On-Chip Oscillator
to Main Clock.
To enter wait mode while using the oscillation stop detection function, set the CM02 bit to “0”
(peripheral function clock does not stop in wait mode).
Since the oscillation stop detection function is a function preparing to stop the main clock by the
external factor, set the OCD1 to OCD0 bits to “00b” (oscillation stop detection function disabled)
when the main clock stops or oscillates in the program, that is stop mode is selected or the CM05
bit is changed.
This function cannot be used when the main clock frequency is below 2 MHz. Set the OCD1 to
OCD0 bits to “00b” (oscillation stop detection function disabled).
When using the low-speed on-chip oscillator clock for the CPU clock and clock sources of
peripheral functions after detecting the oscillation stop, set the HRA01 bit in the HRA0 register to
“0” (low-speed on-chip oscillator selected) and the OCD1 to OCD0 bits to “11b” (oscillation stop
detection function enabled).
When using the high-speed on-chip oscillator clock for the CPU clock and clock sources of
peripheral functions after detecting the oscillation stop, set the HRA01 bit to “1” (high-speed on-
chip oscillator selected) and the OCD1 to OCD0 bits to “11b” (oscillation stop detection function
enabled).
How to Use Oscillation Stop Detection Function
Specification of Oscillation Stop Detection Function
Item
Page 53 of 254
Oscillation stop detection interrupt is generated
f(XIN) ≥ 2 MHz
Set OCD1 to OCD0 bits to “11b” (oscillation stop detection
function enabled)
Specification
9. Clock Generation Circuit