M16C Datasheet, PDF (259/262 Pages) Mitsubishi Electric Semiconductor – SINGLE-CHIP 16-BIT CMOS MICROCOMPUTER

Preliminary Specifications REV.B
Specifications in this manual are tentative and subject to change.
Mitsubishi microcomputers
M16C / 6N Group
Standard Serial I/O Mode
SINGLE-CHIP 16-BIT CMOS MICROCOMPUTER
Status Register 1 (SRD1)
The status register 1 indicates status of serial communication, results of ID checks and those of 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 25-4 gives the definition of each status register bit. "0016" is output when power is turned on and the
flag status is maintained even after the reset.
Table 25-3. Status register 1 (SRD 1)
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"
-
-
-
-
-
-
Match
Mismatch
00 Not verified
01 Verification mismatch
10 Reserved
11 Verified
Time out
Normal operation
-
Block Update Completed Bit (SR15)
This flag indicates whether or not the control program was downloaded to the RAM, using the download
function.
Check Sum Consistency Bit (SR12)
This flag indicates whether or not the check sum matches when a program is downloaded for execution
using the download function.
ID Check Completed Bits (SR11 and SR 10)
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.
259