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R01UH0336EJ0102 Rev.1.02
Page 355 of 1538
Jul 17, 2014
V850E2/PG4-L
Section 10 Safety Guardian (SGA)
10.3.4
Loop-Back Function
The SGA supports a loop-back function which is used to check the error path
from the SGA to the ERROROUT pin. The SGATERRLB is connected to the
ERROROUT pin and the level of the output is reflected to the SGAmSSE131
bit, shown in Table 10-14, SGAmESSTR1 Register Contents.
If a loop-back test is to be run, do so while all error flags that are not masked
by settings in SGAEMK0/1 are clear.
(1)
Example of a Loop-Back Test after Reset
1) After any reset, the error output has a “low level”.
2) Read the SGAMESSTR1.SGAMSSE131 and
SGACESSTR1.SGACSSE131 bits and check for “0”.
3) Clear all internal error sources by the SGAESSTC0 and SGAESSTC1
registers.
4) Mask SG_CMP_ERR by setting the SGAEMK1.SGAEMK108 bit.
5) Set error output to “high level” by the SGAMECLR and SGACECLR
registers.
6) Read the SGAMESSTR1.SGAMSSE131 and
SGACESSTR1.SGACSSE131 bits and check for “1”.
7) Set error output to “low level” by the SGAMESET register.
8) Read the SGAMESSTR1.SGAMSSE131 and
SGACESSTR1.SGACSSE131 bits and check for “0”
9) Clear the error by the SGAESSTC1.SGACLSSE130 bit.
10) Set error output to “high level” by the SGAMECLR register.
11) Read the SGAMESSTR1.SGAMSSE131 and
SGACESSTR1.SGACSSE131 bits and check for “1”.
12) Set error output to “low level” by the SGACESET register.
13) Read the SGAMESSTR1.SGAMSSE131 and
SGACESSTR1.SGACSSE131 bits and check for “0”.
14) Set error output to “low level” by the SGAMESET and SGACESET
registers.
15) Clear the error by the SGAESSTC1.SGACLSSE108 and
SGAESSTC1.SGACLSSE130 bits.
16) Unmask SG_CMP_ERR by clearing the SGAEMK1.SGAEMK108 bit.
Refer to the note in Section 10.4.2 (1), SGAmESET SGAm Error Set Trigger