R5F21324CNSP#U0 Renesas Electronics America, R5F21324CNSP#U0 Datasheet - Page 223

• Manufacturer Part Number: R5F21324CNSP#U0
• Description: MCU 1KB FLASH 16K ROM 20-LSSOP
• Manufacturer: Renesas Electronics America
• Series: R8C/3x/32Cr

Specifications of R5F21324CNSP#U0

• Core Processor: R8C
• Core Size: 16/32-Bit
• Speed: 20MHz
• Connectivity: I²C, LIN, SIO, SSU, UART/USART
• Peripherals: POR, PWM, Voltage Detect, WDT
• Number Of I /o: 15
• Program Memory Size: 16KB (16K x 8)
• Program Memory Type: FLASH
• Ram Size: 1.5K x 8
• Voltage - Supply (vcc/vdd): 1.8 V ~ 5.5 V
• Data Converters: A/D 4x10b
• Oscillator Type: Internal
• Operating Temperature: -20°C ~ 85°C
• Package / Case: 20-LSSOP
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Eeprom Size: -

R8C/32C Group
REJ09B0573-0100 Rev.1.00 Dec. 18, 2009
Page 194 of 573
Figure 17.2
17.3.2
The above applies under the following conditions.
Both bits TSTART and TCSTF in the TRACR register are set to 1 (during count).
Counter of timer RA
Timer RA has a prescaler and a timer (which counts the prescaler underflows). The prescaler and timer each
consist of a reload register and a counter. When writing to the prescaler or timer, values are written to both the
reload register and counter.
However, values are transferred from the reload register to the counter of the prescaler in synchronization with
the count source. In addition, values are transferred from the reload register to the counter of the timer in
synchronization with prescaler underflows. Therefore, if the prescaler or timer is written to when count
operation is in progress, the counter value is not updated immediately after the WRITE instruction is executed.
Figure 17.2 shows an Operating Example of Timer RA when Counter Value is Rewritten during Count
Operation.
timer RA prescaler
timer RA prescaler
Reload register of
Reload register of
IR bit in TRAIC
Count source
Set 01h to the TRAPRE register and 25h to
the TRA register by a program.
Timer Write Control during Count Operation
Counter of
timer RA
register
Operation
Operating Example of Timer RA when Counter Value is Rewritten during Count
0
Previous value
06h
05h
Previous value
The IR bit remains unchanged until underflow is
generated by a new value.
After writing, the reload register is
written to at the first count source.
03h
04h
01h
Reload at
second count
source
00h
After writing, the reload register is
written to at the first underflow.
01h
Reload at
underflow
02h
New value (01h)
00h
Reload at the second underflow
01h
25h
New value (25h)
00h
01h
24h
00h
17. Timer RA