M16C80 Datasheet, PDF (320/358 Pages) Renesas Technology Corp – RENESAS 16-BIT SINGLE-CHIP MICROCOMPUTER M16C FAMILY / M16C/80 SERIES

M16C/80 Group
32. Standard serial I/O mode
Status Register 1 (SRD1)
Status register 1 indicates the status of serial communications, results from ID checks and results from
check 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 31.3 gives the definition of each status register 1 bit. “0016” is output when power is turned ON and
the flag status is maintained even after the reset.
Table 32.3 Status register 1 (SRD1)
SRD1 bits
SR15 (bit7)
SR14 (bit6)
SR13 (bit5)
SR12 (bit4)
SR11 (bit3)
SR10 (bit2)
Status name
Boot update completed bit
Reserved
Reserved
Checksum match bit
ID check completed bits
SR9 (bit1)
SR8 (bit0)
Data receive time out
Reserved
Definition
"1"
"0"
Update completed
Not update
-
-
-
-
Match
00
01
10
11
Mismatch
Not verified
Verification mismatch
Reserved
Verified
Time out
-
Normal operation
-
Boot Update Completed Bit (SR15)
This flag indicates whether the control program was downloaded to the RAM or not, using the down-
load function.
Check Sum Consistency Bit (SR12)
This flag indicates whether the check sum matches or not when a program, is downloaded for execu-
tion using 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 ID
check.
Data Reception Time Out (SR9)
This flag indicates when a time out error is generated during data reception. If this flag is attached
during data reception, the received data is discarded and the microcomputer returns to the command
wait state.
Rev.1.00 Aug. 02, 2005 ^{Page 309} of 329
REJ09B0187-0100