Hello all,
I just was wondering in MSP430f5529 can I use the DMA to transfer a block of
data to an I/O port?
Thanks,
John.
DMA on MSP430F5529
Started by ●September 30, 2012
Reply by ●September 30, 20122012-09-30
i DON'T SPECIFICally use the 5529, but on other MSP430's I have used
with DMA this is simply a case of setting the destination address as the
PxOUT register address, setting the destination to non-increment, and
the source as desired.
Al
On 1/10/2012 12:57 AM, John wrote:
> Hello all,
>
> I just was wondering in MSP430f5529 can I use the DMA to transfer a block of data to an I/O port?
>
> Thanks,
>
> John.
>
>
with DMA this is simply a case of setting the destination address as the
PxOUT register address, setting the destination to non-increment, and
the source as desired.
Al
On 1/10/2012 12:57 AM, John wrote:
> Hello all,
>
> I just was wondering in MSP430f5529 can I use the DMA to transfer a block of data to an I/O port?
>
> Thanks,
>
> John.
>
>
Reply by ●September 30, 20122012-09-30
Thank you Onestone. I do appreciate for your comment,
John.
________________________________
From: Onestone
To: m...
Sent: Sunday, September 30, 2012 9:53 AM
Subject: Re: [msp430] DMA on MSP430F5529
i DON'T SPECIFICally use the 5529, but on other MSP430's I have used
with DMA this is simply a case of setting the destination address as the
PxOUT register address, setting the destination to non-increment, and
the source as desired.
Al
On 1/10/2012 12:57 AM, John wrote:
> Hello all,
>
> I just was wondering in MSP430f5529 can I use the DMA to transfer a block of data to an I/O port?
>
> Thanks,
>
> John.
>
>
John.
________________________________
From: Onestone
To: m...
Sent: Sunday, September 30, 2012 9:53 AM
Subject: Re: [msp430] DMA on MSP430F5529
i DON'T SPECIFICally use the 5529, but on other MSP430's I have used
with DMA this is simply a case of setting the destination address as the
PxOUT register address, setting the destination to non-increment, and
the source as desired.
Al
On 1/10/2012 12:57 AM, John wrote:
> Hello all,
>
> I just was wondering in MSP430f5529 can I use the DMA to transfer a block of data to an I/O port?
>
> Thanks,
>
> John.
>
>
Reply by ●October 1, 20122012-10-01
I may be wrong, but doesn't DMA run at bus speed, and I/O at the speed
of the I/O device?
I would think DMA (bus speed) is different than the I/O device.
Who or what will control the timing difference?
From: m... [mailto:m...] On Behalf
Of Onestone
Sent: Sunday, September 30, 2012 12:53 PM
To: m...
Subject: Re: [msp430] DMA on MSP430F5529
i DON'T SPECIFICally use the 5529, but on other MSP430's I have used
with DMA this is simply a case of setting the destination address as the
PxOUT register address, setting the destination to non-increment, and
the source as desired.
Al
On 1/10/2012 12:57 AM, John wrote:
> Hello all,
>
> I just was wondering in MSP430f5529 can I use the DMA to transfer a
block of data to an I/O port?
>
> Thanks,
>
> John.
>
>
of the I/O device?
I would think DMA (bus speed) is different than the I/O device.
Who or what will control the timing difference?
From: m... [mailto:m...] On Behalf
Of Onestone
Sent: Sunday, September 30, 2012 12:53 PM
To: m...
Subject: Re: [msp430] DMA on MSP430F5529
i DON'T SPECIFICally use the 5529, but on other MSP430's I have used
with DMA this is simply a case of setting the destination address as the
PxOUT register address, setting the destination to non-increment, and
the source as desired.
Al
On 1/10/2012 12:57 AM, John wrote:
> Hello all,
>
> I just was wondering in MSP430f5529 can I use the DMA to transfer a
block of data to an I/O port?
>
> Thanks,
>
> John.
>
>
Reply by ●October 1, 20122012-10-01
The DMA on the MSP430 is not a true independent DMA it 'steals' cycles
from the CPU. The biggest impediment to writing I/O is the MSP430
instruction set, it takes between 4 & 6 cycles to write the I/O port.
DMA at its fastest runs at about 2 cycles, but with efficiently written
code, (perhaps counter intuitively, and depending on whether you define
efficient, as being optimised to streamline DMA transfers or optimised
for code execution) can be much slower, but achieving that means
grabbing the CPU completely. So, in some respects, DMA allows faster I/O
writes. In addition the I/O access speed from DMA would depend on the
DMA mode and trigger source/type.
Al
On 1/10/2012 9:33 PM, Hugo Brunert wrote:
> I may be wrong, but doesn't DMA run at bus speed, and I/O at the speed
> of the I/O device?
>
> I would think DMA (bus speed) is different than the I/O device.
>
> Who or what will control the timing difference?
>
>
>
> From: m... [mailto:m...] On Behalf
> Of Onestone
> Sent: Sunday, September 30, 2012 12:53 PM
> To: m...
> Subject: Re: [msp430] DMA on MSP430F5529
>
>
>
>
>
> i DON'T SPECIFICally use the 5529, but on other MSP430's I have used
> with DMA this is simply a case of setting the destination address as the
>
> PxOUT register address, setting the destination to non-increment, and
> the source as desired.
>
> Al
>
> On 1/10/2012 12:57 AM, John wrote:
>> Hello all,
>>
>> I just was wondering in MSP430f5529 can I use the DMA to transfer a
> block of data to an I/O port?
>> Thanks,
>>
>> John.
>>
>>
>
>>
from the CPU. The biggest impediment to writing I/O is the MSP430
instruction set, it takes between 4 & 6 cycles to write the I/O port.
DMA at its fastest runs at about 2 cycles, but with efficiently written
code, (perhaps counter intuitively, and depending on whether you define
efficient, as being optimised to streamline DMA transfers or optimised
for code execution) can be much slower, but achieving that means
grabbing the CPU completely. So, in some respects, DMA allows faster I/O
writes. In addition the I/O access speed from DMA would depend on the
DMA mode and trigger source/type.
Al
On 1/10/2012 9:33 PM, Hugo Brunert wrote:
> I may be wrong, but doesn't DMA run at bus speed, and I/O at the speed
> of the I/O device?
>
> I would think DMA (bus speed) is different than the I/O device.
>
> Who or what will control the timing difference?
>
>
>
> From: m... [mailto:m...] On Behalf
> Of Onestone
> Sent: Sunday, September 30, 2012 12:53 PM
> To: m...
> Subject: Re: [msp430] DMA on MSP430F5529
>
>
>
>
>
> i DON'T SPECIFICally use the 5529, but on other MSP430's I have used
> with DMA this is simply a case of setting the destination address as the
>
> PxOUT register address, setting the destination to non-increment, and
> the source as desired.
>
> Al
>
> On 1/10/2012 12:57 AM, John wrote:
>> Hello all,
>>
>> I just was wondering in MSP430f5529 can I use the DMA to transfer a
> block of data to an I/O port?
>> Thanks,
>>
>> John.
>>
>>
>
>>
Reply by ●October 1, 20122012-10-01
Thanks Al
From: m... [mailto:m...] On Behalf
Of Onestone
Sent: Monday, October 01, 2012 10:55 AM
To: m...
Subject: Re: [msp430] DMA on MSP430F5529
The DMA on the MSP430 is not a true independent DMA it 'steals' cycles
from the CPU. The biggest impediment to writing I/O is the MSP430
instruction set, it takes between 4 & 6 cycles to write the I/O port.
DMA at its fastest runs at about 2 cycles, but with efficiently written
code, (perhaps counter intuitively, and depending on whether you define
efficient, as being optimised to streamline DMA transfers or optimised
for code execution) can be much slower, but achieving that means
grabbing the CPU completely. So, in some respects, DMA allows faster I/O
writes. In addition the I/O access speed from DMA would depend on the
DMA mode and trigger source/type.
Al
On 1/10/2012 9:33 PM, Hugo Brunert wrote:
> I may be wrong, but doesn't DMA run at bus speed, and I/O at the speed
> of the I/O device?
>
> I would think DMA (bus speed) is different than the I/O device.
>
> Who or what will control the timing difference?
>
> From: m...
[mailto:m... ] On
Behalf
> Of Onestone
> Sent: Sunday, September 30, 2012 12:53 PM
> To: m...
> Subject: Re: [msp430] DMA on MSP430F5529
>
> i DON'T SPECIFICally use the 5529, but on other MSP430's I have used
> with DMA this is simply a case of setting the destination address as
the
>
> PxOUT register address, setting the destination to non-increment, and
> the source as desired.
>
> Al
>
> On 1/10/2012 12:57 AM, John wrote:
>> Hello all,
>>
>> I just was wondering in MSP430f5529 can I use the DMA to transfer a
> block of data to an I/O port?
>> Thanks,
>>
>> John.
>>
>>
>
>>
From: m... [mailto:m...] On Behalf
Of Onestone
Sent: Monday, October 01, 2012 10:55 AM
To: m...
Subject: Re: [msp430] DMA on MSP430F5529
The DMA on the MSP430 is not a true independent DMA it 'steals' cycles
from the CPU. The biggest impediment to writing I/O is the MSP430
instruction set, it takes between 4 & 6 cycles to write the I/O port.
DMA at its fastest runs at about 2 cycles, but with efficiently written
code, (perhaps counter intuitively, and depending on whether you define
efficient, as being optimised to streamline DMA transfers or optimised
for code execution) can be much slower, but achieving that means
grabbing the CPU completely. So, in some respects, DMA allows faster I/O
writes. In addition the I/O access speed from DMA would depend on the
DMA mode and trigger source/type.
Al
On 1/10/2012 9:33 PM, Hugo Brunert wrote:
> I may be wrong, but doesn't DMA run at bus speed, and I/O at the speed
> of the I/O device?
>
> I would think DMA (bus speed) is different than the I/O device.
>
> Who or what will control the timing difference?
>
> From: m...
[mailto:m... ] On
Behalf
> Of Onestone
> Sent: Sunday, September 30, 2012 12:53 PM
> To: m...
> Subject: Re: [msp430] DMA on MSP430F5529
>
> i DON'T SPECIFICally use the 5529, but on other MSP430's I have used
> with DMA this is simply a case of setting the destination address as
the
>
> PxOUT register address, setting the destination to non-increment, and
> the source as desired.
>
> Al
>
> On 1/10/2012 12:57 AM, John wrote:
>> Hello all,
>>
>> I just was wondering in MSP430f5529 can I use the DMA to transfer a
> block of data to an I/O port?
>> Thanks,
>>
>> John.
>>
>>
>
>>
Reply by ●October 1, 20122012-10-01
WELCOME
aL
On 2/10/2012 12:32 AM, Hugo Brunert wrote:
> Thanks Al
>
>
>
> From: m... [mailto:m...] On Behalf
> Of Onestone
> Sent: Monday, October 01, 2012 10:55 AM
> To: m...
> Subject: Re: [msp430] DMA on MSP430F5529
>
>
>
>
>
> The DMA on the MSP430 is not a true independent DMA it 'steals' cycles
> from the CPU. The biggest impediment to writing I/O is the MSP430
> instruction set, it takes between 4 & 6 cycles to write the I/O port.
> DMA at its fastest runs at about 2 cycles, but with efficiently written
> code, (perhaps counter intuitively, and depending on whether you define
> efficient, as being optimised to streamline DMA transfers or optimised
> for code execution) can be much slower, but achieving that means
> grabbing the CPU completely. So, in some respects, DMA allows faster I/O
>
> writes. In addition the I/O access speed from DMA would depend on the
> DMA mode and trigger source/type.
>
> Al
>
> On 1/10/2012 9:33 PM, Hugo Brunert wrote:
>> I may be wrong, but doesn't DMA run at bus speed, and I/O at the speed
>> of the I/O device?
>>
>> I would think DMA (bus speed) is different than the I/O device.
>>
>> Who or what will control the timing difference?
>>
>> From: m...
> [mailto:m... ] On
> Behalf
>> Of Onestone
>> Sent: Sunday, September 30, 2012 12:53 PM
>> To: m...
>> Subject: Re: [msp430] DMA on MSP430F5529
>>
>> i DON'T SPECIFICally use the 5529, but on other MSP430's I have used
>> with DMA this is simply a case of setting the destination address as
> the
>> PxOUT register address, setting the destination to non-increment, and
>> the source as desired.
>>
>> Al
>>
>> On 1/10/2012 12:57 AM, John wrote:
>>> Hello all,
>>>
>>> I just was wondering in MSP430f5529 can I use the DMA to transfer a
>> block of data to an I/O port?
>>> Thanks,
>>>
>>> John.
>>>
>>>
>>>
>>>
>>>
>>>
>
>>
>>>
aL
On 2/10/2012 12:32 AM, Hugo Brunert wrote:
> Thanks Al
>
>
>
> From: m... [mailto:m...] On Behalf
> Of Onestone
> Sent: Monday, October 01, 2012 10:55 AM
> To: m...
> Subject: Re: [msp430] DMA on MSP430F5529
>
>
>
>
>
> The DMA on the MSP430 is not a true independent DMA it 'steals' cycles
> from the CPU. The biggest impediment to writing I/O is the MSP430
> instruction set, it takes between 4 & 6 cycles to write the I/O port.
> DMA at its fastest runs at about 2 cycles, but with efficiently written
> code, (perhaps counter intuitively, and depending on whether you define
> efficient, as being optimised to streamline DMA transfers or optimised
> for code execution) can be much slower, but achieving that means
> grabbing the CPU completely. So, in some respects, DMA allows faster I/O
>
> writes. In addition the I/O access speed from DMA would depend on the
> DMA mode and trigger source/type.
>
> Al
>
> On 1/10/2012 9:33 PM, Hugo Brunert wrote:
>> I may be wrong, but doesn't DMA run at bus speed, and I/O at the speed
>> of the I/O device?
>>
>> I would think DMA (bus speed) is different than the I/O device.
>>
>> Who or what will control the timing difference?
>>
>> From: m...
> [mailto:m... ] On
> Behalf
>> Of Onestone
>> Sent: Sunday, September 30, 2012 12:53 PM
>> To: m...
>> Subject: Re: [msp430] DMA on MSP430F5529
>>
>> i DON'T SPECIFICally use the 5529, but on other MSP430's I have used
>> with DMA this is simply a case of setting the destination address as
> the
>> PxOUT register address, setting the destination to non-increment, and
>> the source as desired.
>>
>> Al
>>
>> On 1/10/2012 12:57 AM, John wrote:
>>> Hello all,
>>>
>>> I just was wondering in MSP430f5529 can I use the DMA to transfer a
>> block of data to an I/O port?
>>> Thanks,
>>>
>>> John.
>>>
>>>
>>>
>>>
>>>
>>>
>
>>
>>>
