R5F21191SP#U0 Renesas Electronics America, R5F21191SP#U0 Datasheet - Page 237

• Manufacturer Part Number: R5F21191SP#U0
• Description: IC R8C MCU FLASH 8K 20SSOP
• Manufacturer: Renesas Electronics America
• Series: M16C™ M16C/R8C/Tiny/19r

Specifications of R5F21191SP#U0

• Core Processor: R8C
• Core Size: 16-Bit
• Speed: 20MHz
• Connectivity: SIO, UART/USART
• Peripherals: LED, POR, Voltage Detect, WDT
• Number Of I /o: 13
• Program Memory Size: 4KB (4K x 8)
• Program Memory Type: FLASH
• Ram Size: 384 x 8
• Voltage - Supply (vcc/vdd): 2.7 V ~ 5.5 V
• Data Converters: A/D 4x1b
• Oscillator Type: Internal
• Operating Temperature: -20°C ~ 85°C
• Package / Case: 20-SSOP
• For Use With: R0K521134S000BE - KIT EVAL STARTER FOR R8C/13R0E521174CPE10 - EMULATOR COMPACT R8C/18/19/1
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Eeprom Size: -

R8C/18 Group, R8C/19 Group
Rev.1.30
REJ09B0222-0130
19.2.6
Sample programs 1 to 3 are for preventing the I flag from being set to 1 (interrupts enabled) before
the interrupt control register is changed for reasons of the internal bus or the instruction queue buffer.
Example 1: Use NOP instructions to prevent I flag from being set to 1 before interrupt control
Example 2: Use dummy read to delay FSET instruction
Example 3: Use POPC instruction to change I flag
(a) The contents of an interrupt control register can only be changed while no interrupt requests
(b) When changing the contents of an interrupt control register after disabling interrupts, be
(c) When disabling interrupts using the I flag, set the I flag as shown in the sample programs
INT_SWITCH1:
INT_SWITCH2:
INT_SWITCH3:
Apr 14, 2006
Changing Interrupt Control Register Contents
corresponding to that register are generated. If interrupt requests may be generated, disable
interrupts before changing the interrupt control register contents.
careful to choose appropriate instructions.
Changing any bit other than IR bit
If an interrupt request corresponding to a register is generated while executing the instruction,
the IR bit may not be set to 1 (interrupt requested), and the interrupt request may be ignored.
If this causes a problem, use the following instructions to change the register: AND, OR,
BCLR, BSET
Changing IR bit
If the IR bit is set to 0 (interrupt not requested), it may not be set to 0 depending on the
instruction used. Therefore, use the MOV instruction to set the IR bit to 0.
below. Refer to (b) regarding changing the contents of interrupt control registers by the sample
programs.
FCLR
AND.B
NOP
NOP
FSET
FCLR
AND.B
MOV.W MEM,R0
FSET
PUSHC FLG
FCLR
AND.B
POPC
register is changed
I
#00H,0056H
I
I
#00H,0056H
I
I
#00H,0056H
FLG
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;
; Disable interrupts
; Set TXIC register to 00h
; Enable interrupts
; Disable interrupts
; Set TXIC register to 00h
; Dummy read
; Enable interrupts
; Disable interrupts
; Set TXIC register to 00h
; Enable interrupts
19. Usage Notes