M16C User Manual.pdf

Appendix Standard Serial I/O Mode (Flash Memory Version)Mitsubishi microcomputersM16C / 62 GroupSINGLE-CHIP 16-BIT CMOS MICROCOMPUTERStatus Register 1 (SRD1)Status register 1 indicates the status of serial communications, results from ID checks and results fromcheck sum comparisons. It can be read after the SRD by writing the read status register command (7016).Also, status register 1 is cleared by writing the clear status register command (5016).Table 1.31.3 gives the definition of each status register 1 bit. “0016” is output when power is turned ONand the flag status is maintained even after the reset.Table 1.31.3. Status register 1 (SRD1)SRD1 bitsSR15 (bit7)SR14 (bit6)SR13 (bit5)SR12 (bit4)SR11 (bit3)SR10 (bit2)Status nameBoot update completed bitReservedReservedChecksum match bitID check completed bitsDefinition"1" "0"Update completed--Match00011011Not update--MismatchNot verifiedVerification mismatchReservedVerifiedSR9 (bit1)Data receive time outTime outNormal operationSR8 (bit0)Reserved--Boot Update Completed Bit (SR15)This flag indicates whether the control program was downloaded to the RAM or not, using the downloadfunction.Check Sum Consistency Bit (SR12)This flag indicates whether the check sum matches or not when a program, is downloaded for executionusing the download function.ID Check Completed Bits (SR11 and SR10)These flags indicate the result of ID checks. Some commands cannot be accepted without an IDcheck.Data Reception Time Out (SR9)This flag indicates when a time out error is generated during data reception. If this flag is attachedduring data reception, the received data is discarded and the microcomputer returns to the commandwait state.269