Hi Josef,
I had a look at this with FRDM-KE02 and FRDM MK20 boards using the USBDM TCL interpreter. I got the following results:
For a FRDM-KE02
% stat
Found 1 devices
USBDM DLL Version = 4.10.6.100
BDM Version = HW=59, SW=4A
USBDM DLL Version = 4.10.6.100
BDM Version = HW=59, SW=4A
:setTarget ARM
:connect
With reset low
:pinSet 0x8
:rCreg r=0x1000000(MDM_AP.Status)->0x00000000
:rCreg r=0x1000004(MDM_AP.Control)->0x00000000
:rCreg r=0x10000FC(MDM_AP.Ident)->0x001C0020
With reset high
:pinSet 0x4
:rCreg r=0x1000000(MDM_AP.Status)->0x0001000A
:rCreg r=0x1000004(MDM_AP.Control)->0x00000000
:rCreg r=0x10000FC(MDM_AP.Ident)->0x001C0020
FRDM-MK20
% stat
Found 1 devices
USBDM DLL Version = 4.10.6.100
BDM Version = HW=59, SW=4A
USBDM DLL Version = 4.10.6.100
BDM Version = HW=59, SW=4A
:setTarget ARM
:connect
With reset low
:pinSet 0x8
:rCreg r=0x1000000(MDM_AP.Status)->0x00000032
:rCreg r=0x1000004(MDM_AP.Control)->0x00000000
:rCreg r=0x10000FC(MDM_AP.Ident)->0x001C0000
With reset high
:pinSet 0x4
:rCreg r=0x1000000(MDM_AP.Status)->0x0001003A
:rCreg r=0x1000004(MDM_AP.Control)->0x00000000
:rCreg r=0x10000FC(MDM_AP.Ident)->0x001C0000
1835008
This was using the following TCL script:
set ::status 0x01000000
set ::control 0x01000004
set ::idreg 0x010000FC
proc stat {} {
openbdm
settarget arm
connect
puts "With reset pin low"
pinSet rst=0
rcreg $::status
rcreg $::control
rcreg $::idreg
puts "With reset pin 3-state"
pinSet rst=3
rcreg $::status
rcreg $::control
rcreg $::idreg
}
This would confirm your conclusion that the mdm-ap-status register reads zero when the device is being held in reset by the reset pin. This is different from the MK20.
bye