R5F21274SNFP#U0 Renesas Electronics America, R5F21274SNFP#U0 Datasheet - Page 458

• Manufacturer Part Number: R5F21274SNFP#U0
• Description: IC R8C/27 MCU FLASH 32LQFP
• Manufacturer: Renesas Electronics America
• Series: R8C/2x/27r

Specifications of R5F21274SNFP#U0

• Core Processor: R8C
• Core Size: 16/32-Bit
• Speed: 20MHz
• Connectivity: I²C, LIN, SIO, SSU, UART/USART
• Peripherals: LED, POR, Voltage Detect, WDT
• Number Of I /o: 25
• Program Memory Size: 16KB (16K x 8)
• Program Memory Type: FLASH
• Ram Size: 1K x 8
• Voltage - Supply (vcc/vdd): 2.2 V ~ 5.5 V
• Data Converters: A/D 12x10b
• Oscillator Type: Internal
• Operating Temperature: -20°C ~ 85°C
• Package / Case: 32-LQFP
• For Use With: R0K521276S000BE - KIT DEV RSK-R8C/26-29R0E521000EPB00 - PROBE EMULATOR FOR PC7501
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Eeprom Size: -

R8C/26 Group, R8C/27 Group
Rev.2.10
REJ09B0278-0210
21.3.4.3
In real-time clock mode, read registers TRESEC, TREMIN, TREHR, and TREWK when time data is updated
and read the PM bit in the TRECR1 register when the BSY bit is set to 0 (not while data is updated).
Also, when reading several registers, an incorrect time will be read if data is updated before another register is
read after reading any register.
In order to prevent this, use the reading procedure shown below.
• Using an interrupt
• Monitoring with a program 1
• Monitoring with a program 2
(1) Monitor the BSY bit.
(2) Monitor until the BSY bit is set to 0 after the BSY bit is set to 1 (approximately 62.5 ms while the BSY
(3) Read necessary contents of registers TRESEC, TREMIN, TREHR, and TREWK and the PM bit in the
• Using read results if they are the same value twice
(1) Read necessary contents of registers TRESEC, TREMIN, TREHR, and TREWK and the PM bit in the
(2) Read the same register as (1) and compare the contents.
(3) Recognize as the correct value if the contents match. If the contents do not match, repeat until the read
Sep 26, 2008
Read necessary contents of registers TRESEC, TREMIN, TREHR, and TREWK and the PM bit in the
TRECR1 register in the timer RE interrupt routine.
Monitor the IR bit in the TREIC register with a program and read necessary contents of registers TRESEC,
TREMIN, TREHR, and TREWK and the PM bit in the TRECR1 register after the IR bit in the TREIC
register is set to 1 (timer RE interrupt request generated).
Also, when reading several registers, read them as continuously as possible.
bit is set to 1).
TRECR1 register after the BSY bit is set to 0.
TRECR1 register.
contents match with the previous contents.
Time Reading Procedure of Real-Time Clock Mode
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21. Usage Notes