Dear Expert:
About i.mx6ull-evk,I have questions below,please help answer,thanks.
1. this picture is from the MCIMX6ULL-CM Page 10:
a. what function is this signal "GPIO_DVFS"?
b. Is ther a current size requirement about Q702 and Q707? If yes, is the 230mA enough?
c.Q701 is different Q702 and Q707,is there any special?
2. this picture is from the MCIMX6ULL-CM Page 10 too:
could you tell me whether this circuitry is software watchdog or not?How work?
C738 is a capacity, how is this signal "nWDOG" control UM805RE?
pls help,thanks.
Dear Expert:
OK,thanks for your support.
BRs
Tom
Dear Expert:
thanks for your answer.
Furthermore:
1. how to comprehend?
what change is the DVFS when system reboot?
2. in this picture,C738 is a capacity,so could you tell me What is the Electrical property of the signal nWDOG,pulse or level,and is this need the software to controll?
thanks for your support.
BRs
Tom
Hi Tom
DVFS may lower voltage so processor will not reboot.
For example , if just before reboot it is under lowest cpu freq setpoint ,
low voltage can not make system boot up at default frequency (as after power-up).
For nWDOG there is no software to control of pulse or level.
~igor
Hi Tom
-GPIO_DVFS implements changing arm core voltage for cpufreq driver
-there is no special size requirement for Q701,702, as for Q707 it discharges
VDD_ARM_SOC_IN voltage so may be recommended to use the same type
as used on EVK
-MCIMX6ULL-CM Page 10 implements board reset function used for software
reboot, it is the same solution as for i.MX6Q Sabre SD board spf-27392 p.21,
that is toggle all power board for reliable reboot.
Best regards
igor
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