LPCXpresso IDEのトピックRe: LPC1114 - bidirectional IO port

LPC1114 - bidirectional IO port

lpcware — Wed, 15 Jun 2016 22:34:58 GMT

Content originally posted in LPCWare by plebi on Thu Mar 31 05:42:44 MST 2011
hi,
Im using small_gpio library to change states of IO ports and functions of IO ports.
Everythings works well instead of ports 1.1 and 1.0.
At start im changing functions of these ports to GPIO, pullup, and output (after reset were different).
And then,
Port 1_1 works sometimes as input, sometimes as output - his function has been chaged because it works as bidirectional data port.
Simple:
port 1_1 - bidirectional data
port 1_0 - output clock
and there is a problem with changing function of 1_1 port from input to output.
When function is changed to output (from input) and his state should be HI (3V) on port I measure about 0.5V !!. And this value has been changed to 3V when on CLK port (1_0) value is chaged to HIGH.
Instead of this one (first) pulse ports works well.
Change from output to input works also well.
Can anyone help me and explain why ?
On both IO ports are connected resistors 10k to VCC(3V) as external pull up.
Problem was ilustrated on picture below.
Thnax
plebi

Re: LPC1114 - bidirectional IO port

lpcware — Wed, 15 Jun 2016 22:34:59 GMT

Content originally posted in LPCWare by Ex-Zero on Thu Mar 31 06:00:24 MST 2011
Please use debugger to control IOCON_R_PIO1_0 / IOCON_R_PIO1_1 settings.

Re: LPC1114 - bidirectional IO port

lpcware — Wed, 15 Jun 2016 22:34:59 GMT

Content originally posted in LPCWare by plebi on Thu Mar 31 06:29:45 MST 2011
Register                                           Address           Value
IOCON_JTAG_TDO_PIO1_1   0x4004407c      0xd1
ADMODE                                            [7]          DIGITAL
HYS                                                      [5]        HYSTERESISOFF
MODE                                                [4:3]           PULLUP
FUNC                                                 [2:0]        PIO1_1   2

            Register                                            Address           Value
IOCON_JTAG_TDO_PIO1_1   0x4004407c       0xd1
ADMODE                                             [7]             DIGITAL
HYS                                                       [5]               HYSTERESISOFF
MODE                                                 [4:3]              PULLUP
FUNC                                                  [2:0]              PIO1_1   2

Re: LPC1114 - bidirectional IO port

lpcware — Wed, 15 Jun 2016 22:35:00 GMT

Content originally posted in LPCWare by Ex-Zero on Thu Mar 31 07:08:15 MST 2011
0xd1 is OK.

Quote:

And this value has been changed to 3V when on CLK port (1_0) value is chaged to HIGH.

:confused::confused:

Which hardware are you using? Is there anything connected to this pins, did you look for unintended connections?

Whats happening if you don't switch PIO1_0?

Can you (reduce your code to the basic problem and) post it?

Re: LPC1114 - bidirectional IO port

lpcware — Wed, 15 Jun 2016 22:35:01 GMT

Content originally posted in LPCWare by plebi on Thu Mar 31 10:29:41 MST 2011
Thanx for help :)
Sometimes anyone needs a little break at job. When I came to home I've found a reason (probably, solution not tested but im pretty sure).
Another IC (connected to this port) block that line (pull down) and unblock after CLK. I'll check it tomorrow.