r5f21368sdfp Renesas Electronics Corporation., r5f21368sdfp Datasheet - Page 478

• Manufacturer Part Number: r5f21368sdfp
• Description: Renesas Mcu R8c Family / R8c/3xt-a Series
• Manufacturer: Renesas Electronics Corporation.

Under development
R8C/36T-A Group
R01UH0240EJ0001 Rev.0.01
Apr 28, 2011
20.4.3.4
20.4.3.5
20.4.3.6
(1) Setup and Hold Times
Setup time and hold time at start condition/stop condition detection may differ from the I
Setup time and hold time at start condition/stop condition detection are as follows:
Setup time > 5 cycles (f1 clock)
Hold time > 5 cycles (f1 clock)
In the I
speed mode. The setup and hold times of UART2 are a minimum of five cycles (f1 clock). Consequently, when
an 8 MHz f1 clock is used, the setup and hold times are a minimum of 625 ns and thus meet the I
standard for high-speed mode. However, if the main clock is used at less than 8 MHz, the setup and hold times
cannot meet the I
During transmission, 8-bit transmit data is transmitted from the SDA2 pin. In order to receive an acknowledge,
the SDA2 pin must be released at the 9th bit of the transmit clock. To achieve this, 1 must always be written to
the 9th bit (D8) of transmit data.
During reception, the SDA2 pin must be released while it is receiving 8-bit data. In addition, an acknowledge
needs to be generated at the 9th bit of the transmit clock. To achieve this, write 1 to D7 to D0 as dummy data
during reception. D8 is ACK/NACK. ACK/NACK can be transmitted using the following three methods:
The arbitration detection flag is set when an acknowledge is received, so clear this flag when starting
transmission and then perform transmission.
1. Use bits ACKC and ACKD in the U2SMR4 register to transmit ACK/NACK (in this case, the value of D8
2. Use 0 as dummy data for D8. If ACK is returned, transmit as is. If NACK is returned, leave the SDA2 pin
3. Use 0 as dummy data for D8. If ACK is returned, transmit as is. If NACK is returned, leave the SDA2 pin
is not used).
open by setting the SDHI bit to 1.
open using port control.
2
C standard, the start and stop condition setup and hold times are both a minimum of 600 ns in high-
Preliminary document
Specifications in this document are tentative and subject to change.
Start and Stop Conditions
Transmission and Reception
Arbitration
2
C standard for high-speed mode.
20. Serial Interface (UART2)
2
C standard.
Page 447 of 725
2
C bus