74
3850 Group (Spec. H/A)
SINGLE-CHIP 8-BIT CMOS MICROCOMPUTER
MITSUBISHI MICROCOMPUTERS
G
Status Register 1 (SRD1)
The status register 1 indicates the status of serial communica-
tions, results from ID checks and results from check sum
comparisons. It can be read after the status register (SRD) by writ-
ing the read status register command (70
16
). Also, status register
1 is cleared by writing the clear status register command (50
16
).
Table 17 lists the definition of each status register 1 bit. This regis-
ter becomes
“
00
16
”
when power is turned on and the flag status is
maintained even after the reset.
Table 17 Definition of each bit of status register 1 (SRD1)
00
01
10
11
Time out
-
Not verified
Verification mismatch
Reserved
Verified
Normal operation
SR15 (bit7)
SR14 (bit6)
SR13 (bit5)
SR12 (bit4)
SR11 (bit3)
SR10 (bit2)
SR9 (bit1)
SR8 (bit0)
Boot update completed bit
Reserved
Reserved
Checksum match bit
ID check completed bits
Data reception time out
Reserved
“
1
”
Update completed
-
-
Match
“
0
”
Not Update
-
-
Mismatch
-
Definition
SRD1 bits
Status name
Boot update completed bit (SR15)
This flag indicates whether the control program was downloaded
to the RAM or not, using the download function.
Check sum consistency bit (SR12)
This flag indicates whether the check sum matches or not when a
program, is downloaded for execution using the download func-
tion.
ID check completed bits (SR11 and SR10)
These flags indicate the result of ID checks. Some commands
cannot be accepted without an ID code 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 re-
ceived data is discarded and the MCU returns to the command
wait state.