LPCXpresso IDEのトピックClearing a bit in SYSAHBCLKCTRL

Clearing a bit in SYSAHBCLKCTRL

lpcware — Wed, 15 Jun 2016 23:38:52 GMT

Content originally posted in LPCWare by ECamino on Mon Mar 11 07:00:02 MST 2013
Hi,

I'm working with LPC1347. I'm having trouble with IAP call for bootloading. It's intermittent even after disabling all peripheral timers. I think the problem is my USART. I would like to turn off/disable the previously enabled USART peripheral.

Stepping through and watching SYSCON. I see that both these lines of code disables ALL the bits in SYSAHBCLKCTRL, except SYS (b0).
[SIZE=2]
LPC_SYSCON->[/SIZE][SIZE=2][COLOR=#0000c0][SIZE=2][COLOR=#0000c0]SYSAHBCLKCTRL[/COLOR][/SIZE][/COLOR][/SIZE][SIZE=2] &= (0<<12); [/SIZE]
[SIZE=2]LPC_SYSCON->[/SIZE][SIZE=2][COLOR=#0000c0][SIZE=2][COLOR=#0000c0]SYSAHBCLKCTRL[/COLOR][/SIZE][/COLOR][/SIZE][SIZE=2] &= 0xFFFFEFFF; [/SIZE]
[SIZE=2][/SIZE]
[SIZE=2]I just want to clear SYSAHBCLKCTRL b12. Why doesn't the code above work and how do you clear a single bit in SYSAHBCLKCTRL?[/SIZE]
[SIZE=2][/SIZE]
[SIZE=2]Thanks,[/SIZE]
[SIZE=2][/SIZE]
[SIZE=2]EC[/SIZE]

Re: Clearing a bit in SYSAHBCLKCTRL

lpcware — Wed, 15 Jun 2016 23:38:53 GMT

Content originally posted in LPCWare by Ex-Zero on Mon Mar 11 07:08:57 MST 2013

Quote: ECamino

[SIZE=2]I just want to clear SYSAHBCLKCTRL b12. Why doesn't the code above work and how do you clear a single bit in SYSAHBCLKCTRL?[/SIZE]

Then just clear bit 12

[B][SIZE=2]LPC_SYSCON->[/SIZE][SIZE=2][COLOR=#0000c0][SIZE=2][COLOR=#0000c0]SYSAHBCLKCTRL[/COLOR][/SIZE][/COLOR][/SIZE][SIZE=2][COLOR=Red] &= ~[/COLOR]([COLOR=SeaGreen]1[/COLOR]<<12); [/SIZE][/B]

Re: Clearing a bit in SYSAHBCLKCTRL

lpcware — Wed, 15 Jun 2016 23:38:53 GMT

Content originally posted in LPCWare by ECamino on Mon Mar 11 07:17:28 MST 2013
[SIZE=2]Sorry, should have said I tried this too: LPC_SYSCON->[/SIZE][SIZE=2][COLOR=#0000c0][SIZE=2][COLOR=#0000c0]SYSAHBCLKCTRL[/COLOR][/SIZE][/COLOR][/SIZE][SIZE=2] &= ~(1<<12); [/SIZE]
[SIZE=2][COLOR=#3f7f5f][/COLOR][/SIZE]
[SIZE=2][COLOR=black]Doesn't work either!:confused:[/COLOR][/SIZE]

Re: Clearing a bit in SYSAHBCLKCTRL

lpcware — Wed, 15 Jun 2016 23:38:54 GMT

Content originally posted in LPCWare by Ex-Zero on Mon Mar 11 07:38:18 MST 2013
:confused:

That's correct code and working here with other MCUs :)

So what's happening if you switch bit 12 in debugger?

Re: Clearing a bit in SYSAHBCLKCTRL

lpcware — Wed, 15 Jun 2016 23:38:54 GMT

Content originally posted in LPCWare by ECamino on Tue Mar 12 06:13:55 MST 2013
Very strange! Today both lines below are now working...must have been some kind error that cleared when rebooted PC today?

[SIZE=2]LPC_SYSCON->[COLOR=#0000c0][COLOR=#0000c0]SYSAHBCLKCTRL[/COLOR][/COLOR] &= ~(1<<12); [/SIZE]
[SIZE=2]LPC_SYSCON->[/SIZE][SIZE=2][COLOR=#0000c0][SIZE=2][COLOR=#0000c0]SYSAHBCLKCTRL[/COLOR][/SIZE][/COLOR][/SIZE][SIZE=2] &= 0xFFFFEFFF; [/SIZE]

Thanks,

EC