If a port pin was configured as I/O in the beginning for non /01 chip, and then
later on was swap with /01 version with SCS = 3, but leave the rest of the fast
port registers at reset default values, what will happen?
On the other hand, if all the port registers have been changed to fast port
registers, but SCS was accidentally left at default 0, what will happen?
Why not NXP just use the same set of port registers to configure the ports and
let SCS register only to decide if fast GPIO or slow GPIO is intended?
Fast GPIO vs Slow GPIO on /01
Started by ●August 19, 2011
Reply by ●August 19, 20112011-08-19
If I understand correctly you are asking what will happen if you use IODIR,
IOPIN, IOSET, IOCLR while the SCS bit is set to use the fast GPIO, you will not
get any change in the state of the pins, when you set the SCS for fast GPIO the
legacy bus is disconnected and can't change the pin state.
The same problem will occur if you use FIODIR, FIOPIN, FIOSET, FIOCLR while the SCS is set for legacy GPIO
There has been a similar discussed in an older thread
http://tech.groups.yahoo.com/group/lpc2000/message/53617
Alex
--
http://alexan.edaboard.eu
----- Original Message -----
From: hschew00
To: l...
Sent: Friday, August 19, 2011 3:20 PM
Subject: [lpc2000] Fast GPIO vs Slow GPIO on /01
If a port pin was configured as I/O in the beginning for non /01 chip, and then later on was swap with /01 version with SCS = 3, but leave the rest of the fast port registers at reset default values, what will happen?
On the other hand, if all the port registers have been changed to fast port registers, but SCS was accidentally left at default 0, what will happen?
Why not NXP just use the same set of port registers to configure the ports and let SCS register only to decide if fast GPIO or slow GPIO is intended?
The same problem will occur if you use FIODIR, FIOPIN, FIOSET, FIOCLR while the SCS is set for legacy GPIO
There has been a similar discussed in an older thread
http://tech.groups.yahoo.com/group/lpc2000/message/53617
Alex
--
http://alexan.edaboard.eu
----- Original Message -----
From: hschew00
To: l...
Sent: Friday, August 19, 2011 3:20 PM
Subject: [lpc2000] Fast GPIO vs Slow GPIO on /01
If a port pin was configured as I/O in the beginning for non /01 chip, and then later on was swap with /01 version with SCS = 3, but leave the rest of the fast port registers at reset default values, what will happen?
On the other hand, if all the port registers have been changed to fast port registers, but SCS was accidentally left at default 0, what will happen?
Why not NXP just use the same set of port registers to configure the ports and let SCS register only to decide if fast GPIO or slow GPIO is intended?
Reply by ●August 19, 20112011-08-19
Thanks Alex. That answered my doubts.
--- In l..., "Alexan_e" wrote:
>
> If I understand correctly you are asking what will happen if you use IODIR, IOPIN, IOSET, IOCLR while the SCS bit is set to use the fast GPIO, you will not get any change in the state of the pins, when you set the SCS for fast GPIO the legacy bus is disconnected and can't change the pin state.
> The same problem will occur if you use FIODIR, FIOPIN, FIOSET, FIOCLR while the SCS is set for legacy GPIO
>
> There has been a similar discussed in an older thread
> http://tech.groups.yahoo.com/group/lpc2000/message/53617
> Alex
> --
> http://alexan.edaboard.eu
> ----- Original Message -----
> From: hschew00
> To: l...
> Sent: Friday, August 19, 2011 3:20 PM
> Subject: [lpc2000] Fast GPIO vs Slow GPIO on /01
>
> If a port pin was configured as I/O in the beginning for non /01 chip, and then later on was swap with /01 version with SCS = 3, but leave the rest of the fast port registers at reset default values, what will happen?
>
> On the other hand, if all the port registers have been changed to fast port registers, but SCS was accidentally left at default 0, what will happen?
>
> Why not NXP just use the same set of port registers to configure the ports and let SCS register only to decide if fast GPIO or slow GPIO is intended?
>
--- In l..., "Alexan_e" wrote:
>
> If I understand correctly you are asking what will happen if you use IODIR, IOPIN, IOSET, IOCLR while the SCS bit is set to use the fast GPIO, you will not get any change in the state of the pins, when you set the SCS for fast GPIO the legacy bus is disconnected and can't change the pin state.
> The same problem will occur if you use FIODIR, FIOPIN, FIOSET, FIOCLR while the SCS is set for legacy GPIO
>
> There has been a similar discussed in an older thread
> http://tech.groups.yahoo.com/group/lpc2000/message/53617
> Alex
> --
> http://alexan.edaboard.eu
> ----- Original Message -----
> From: hschew00
> To: l...
> Sent: Friday, August 19, 2011 3:20 PM
> Subject: [lpc2000] Fast GPIO vs Slow GPIO on /01
>
> If a port pin was configured as I/O in the beginning for non /01 chip, and then later on was swap with /01 version with SCS = 3, but leave the rest of the fast port registers at reset default values, what will happen?
>
> On the other hand, if all the port registers have been changed to fast port registers, but SCS was accidentally left at default 0, what will happen?
>
> Why not NXP just use the same set of port registers to configure the ports and let SCS register only to decide if fast GPIO or slow GPIO is intended?
>
