R5F21257SNFP#U0 Renesas Electronics America, R5F21257SNFP#U0 Datasheet - Page 488

• Manufacturer Part Number: R5F21257SNFP#U0
• Description: IC R8C/25 MCU FLASH 52LQFP
• Manufacturer: Renesas Electronics America
• Series: R8C/2x/25r

Specifications of R5F21257SNFP#U0

• Core Processor: R8C
• Core Size: 16/32-Bit
• Speed: 20MHz
• Connectivity: I²C, LIN, SIO, SSU, UART/USART
• Peripherals: POR, Voltage Detect, WDT
• Number Of I /o: 41
• Program Memory Size: 48KB (48K x 8)
• Program Memory Type: FLASH
• Ram Size: 2.5K 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: 52-LQFP
• For Use With: R0K521256S000BE - KIT EVAL STARTER FOR R8C/25
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Eeprom Size: -

R8C/24 Group, R8C/25 Group
Rev.3.00
REJ09B0244-0300
21.3.4
21.3.4.1
21.3.4.2
Timer RE has the TSTART bit for instructing the count to start or stop, and the TCSTF bit, which indicates
count start or stop. Bits TSTART and TCSTF are in the TRECR1 register.
Timer RE starts counting and the TCSTF bit is set to 1 (count starts) when the TSTART bit is set to 1 (count
starts). It takes up to 2 cycles of the count source until the TCSTF bit is set to 1 after setting the TSTART bit to
1. During this time, do not access registers associated with timer RE
Also, timer RE stops counting when setting the TSTART bit to 0 (count stops) and the TCSTF bit is set to 0
(count stops). It takes the time for up to 2 cycles of the count source until the TCSTF bit is set to 0 after setting
the TSTART bit to 0. During this time, do not access registers associated with timer RE other than the TCSTF
bit.
NOTE:
Write to the following registers or bits when timer RE is stopped.
Timer RE is stopped when bits TSTART and TCSTF in the TRECR1 register are set to 0 (timer RE stopped).
Also, set all above-mentioned registers and bits (immediately before timer RE count starts) before setting the
TRECR2 register.
Figure 21.8 shows a Setting Example in Real-Time Clock Mode.
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•
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1. Registers associated with timer RE: TRESEC, TREMIN, TREHR, TREWK, TRECR1, TRECR2, and
Feb 29, 2008
Registers TRESEC, TREMIN, TREHR, TREWK, and TRECR2
Bits H12_H24, PM, and INT in TRECR1 register
Bits RCS0 to RCS3 in TRECSR register
Notes on Timer RE
Starting and Stopping Count
Register Setting
Page 469 of 485
TRECSR.
(1)
other than the TCSTF bit.
21. Usage Notes