M16CSLASH62 datasheet(158/621 Pages) RENESAS

158 / 621 page

Mitsubishi microcomputers

M16C / 62 Group

SINGLE-CHIP 16-BIT CMOS MICROCOMPUTER

UART2 Special Mode Register

143

The acknowledgment non-detection interrupt refers to the interrupt that occurs when the SDA terminal

level is detected still staying “H” at the rising edge of the 9th transmission clock. The acknowledgment

detection interrupt refers to the interrupt that occurs when SDA terminal’s level is detected already went

to “L” at the 9th transmission clock. Also, assigning 1 1 0 1 (UART2 reception) to the DMA1 request factor

select bits provides the means to start up the DMA transfer by the effect of acknowledgment detection.

Bit 1 of the UART2 special mode register (037716) is used as the arbitration loss detecting flag control bit.

Arbitration means the act of detecting the nonconformity between transmission data and SDA terminal

data at the timing of the SCL rising edge. This detecting flag is located at bit 3 of the UART2 reception

buffer register (037F16), and “1” is set in this flag when nonconformity is detected. Use the arbitration lost

detecting flag control bit to choose which way to use to update the flag, bit by bit or byte by byte. When

setting this bit to “1” and updated the flag byte by byte if nonconformity is detected, the arbitration lost

detecting flag is set to “1” at the falling edge of the 9th transmission clock.

If update the flag byte by byte, must judge and clear (“0”) the arbitration lost detecting flag after complet-

ing the first byte acknowledge detect and before starting the next one byte transmission.

Bit 3 of the UART2 special mode register is used as SCL- and L-synchronous output enable bit. Setting

this bit to “1” goes the P71 data register to “0” in synchronization with the SCL terminal level going to “L”.

M16C/62 Datasheet(PDF) 158 Page - Renesas Technology Corp