Lpc2000

Does anyone have experience with the Jeeni connected to an lpc2xxx?
I got a Jeeni (from EPI) on my desk but heard that it will not connect 
to the lpc2xxx because of the missing RTCK line on its JTAG interface.

I was not yet able to verify this myself yet since I'm still waiting for 
the software to arrive (someone misplaced the CDs ...)

Rob

--- In lpc2000@yahoogroups.com, Rob Jansen <rob@m...> wrote:
> Does anyone have experience with the Jeeni connected to an lpc2xxx?
> I got a Jeeni (from EPI) on my desk but heard that it will not connect 
> to the lpc2xxx because of the missing RTCK line on its JTAG interface.
> 
> I was not yet able to verify this myself yet since I'm still waiting
for 
> the software to arrive (someone misplaced the CDs ...)

I was informed unequivocally by EPI that the LPC family (and any other
-S series ARM core) was *not* supported by JEENI specifically due to
the lack of the RTCK interface.  This is what forced me to buy another
JTAG unit to work with the LPCs, specifically, a BDI2000, since I
needed to continue to use the GDB server-based interface.

Abitron also stated that the RTCK support was mandatory, quoting the
same paragraph from the ARM7DMI-S spec noted in an earlier message. 
If this pin really isn't necessary for correct data timing, then
Philips needs to get the message out to all the JTAG debugger people.

-- Tom Nelson

Hi Tom,

The RTCK isn't strictly needed. Without the RTCK if the JTAG port works 
slowly, as is the case of the LPC2xxx, then the JTAG cable/debugger has 
to put in a delay before it samples the TDO. I'm surprised that 
companies are selling JTAG cables that require RTCK - the cynic in me 
says it's a way of getting repeat business.

Michael

>--- In lpc2000@yahoogroups.com, Rob Jansen <rob@m...> wrote:
>  
>
>>Does anyone have experience with the Jeeni connected to an lpc2xxx?
>>I got a Jeeni (from EPI) on my desk but heard that it will not connect 
>>to the lpc2xxx because of the missing RTCK line on its JTAG interface.
>>
>>I was not yet able to verify this myself yet since I'm still waiting
>>    
>>
>for 
>  
>
>>the software to arrive (someone misplaced the CDs ...)
>>    
>>
>
>I was informed unequivocally by EPI that the LPC family (and any other
>-S series ARM core) was *not* supported by JEENI specifically due to
>the lack of the RTCK interface.  This is what forced me to buy another
>JTAG unit to work with the LPCs, specifically, a BDI2000, since I
>needed to continue to use the GDB server-based interface.
>
>Abitron also stated that the RTCK support was mandatory, quoting the
>same paragraph from the ARM7DMI-S spec noted in an earlier message. 
>If this pin really isn't necessary for correct data timing, then
>Philips needs to get the message out to all the JTAG debugger people.
>
>-- Tom Nelson
>
>
>
>
>
>
>
> 
>Yahoo! Groups Links
>
>
>
> 
>
>
>  
>

From: "Michael Johnson"
> The RTCK isn't strictly needed. Without the RTCK if the JTAG port works
> slowly, as is the case of the LPC2xxx, then the JTAG cable/debugger has
> to put in a delay before it samples the TDO. I'm surprised that
> companies are selling JTAG cables that require RTCK - the cynic in me
> says it's a way of getting repeat business.

AFAIK:

(1) Use of RTCK for PLL'ed MCUs.

It is extremely useful when you have an MCU that starts at a slow speed,
then turns on a PLL and speeds up. The RTCK then continuously indicates the
speed at which you can clock instructions into the core and the JTAG can
track that speed.

Normally in setups like this the PLL registers are programmed first, then
the RAM is uploaded. The increase in upload speed is equal to the PLL
multiplier.

(2) Use of RTCK to synchronize JTAG to the core execution.

When you don't know the core clock you may have to wait a few CLK states
after loading each instruction into the pipeline so you are sure it is
executed before the JTAG sends in the next instruction.
By using RTCK you can syncronize this process and skip a few waitstates.


Regards,
Arie de Muynck

Hi Arie,

I would agree that the RTCK is useful. This thread started when someone 
wanted to throw away JTAG pins. I would throw away TRST (tap reset - 
which can be done via JTAG) rather than RTCK.

Regards
Michael

>From: "Michael Johnson"
>  
>
>>The RTCK isn't strictly needed. Without the RTCK if the JTAG port works
>>slowly, as is the case of the LPC2xxx, then the JTAG cable/debugger has
>>to put in a delay before it samples the TDO. I'm surprised that
>>companies are selling JTAG cables that require RTCK - the cynic in me
>>says it's a way of getting repeat business.
>>    
>>
>
>AFAIK:
>
>(1) Use of RTCK for PLL'ed MCUs.
>
>It is extremely useful when you have an MCU that starts at a slow speed,
>then turns on a PLL and speeds up. The RTCK then continuously indicates the
>speed at which you can clock instructions into the core and the JTAG can
>track that speed.
>
>Normally in setups like this the PLL registers are programmed first, then
>the RAM is uploaded. The increase in upload speed is equal to the PLL
>multiplier.
>
>(2) Use of RTCK to synchronize JTAG to the core execution.
>
>When you don't know the core clock you may have to wait a few CLK states
>after loading each instruction into the pipeline so you are sure it is
>executed before the JTAG sends in the next instruction.
>By using RTCK you can syncronize this process and skip a few waitstates.
>
>
>Regards,
>Arie de Muynck
>
>
>
>
> 
>Yahoo! Groups Links
>
>
>
> 
>
>
>
>  
>

To add to the benefits of RTCK:

How would one enable debug without the RTCK pin?

Excerpt from a Data Sheet:
"RTCK - Returned Test Clock output. Extra signal added to the JTAG port.
Assists debugger synchronization when processor frequency varies.
Bidirectional pin with internal pull-up.
Note: LOW on RTCK while RESET is LOW enables pins P1.31:26 to operate
as Debug port after reset."

Pins P1.31:26 are the JTAG port.

Regards
Joel

Joel,

the LPC2103 has a dedicated debug enable pin which enables the JTAG. 

Bob

--- In lpc2000@yahoogroups.com, "Joel Winarske" <joelw@i...> wrote:

> To add to the benefits of RTCK:
> 
> How would one enable debug without the RTCK pin?
> 
> Excerpt from a Data Sheet:
> "RTCK - Returned Test Clock output. Extra signal added to the JTAG port.
> Assists debugger synchronization when processor frequency varies.
> Bidirectional pin with internal pull-up.
> Note: LOW on RTCK while RESET is LOW enables pins P1.31:26 to operate
> as Debug port after reset."
> 
> Pins P1.31:26 are the JTAG port.
> 
> Regards
> Joel

> the LPC2103 has a dedicated debug enable pin which enables the JTAG. 
> 
> Bob

My bad.  I was referencing the LPC214x data sheet.

Not sure is you know this but EPI has seized to
support the Jeenie and recommend the Majic-LX, there
is still some issues with the RTCK when you init. the
LPC2xxx, so you shoud be very careful when you write
the startice.cmd. 

regards

Samuel

--- Rob Jansen <rob@...> wrote:

> Does anyone have experience with the Jeeni connected
> to an lpc2xxx?
> I got a Jeeni (from EPI) on my desk but heard that
> it will not connect 
> to the lpc2xxx because of the missing RTCK line on
> its JTAG interface.
> 
> I was not yet able to verify this myself yet since
> I'm still waiting for 
> the software to arrive (someone misplaced the CDs
> ...)
> 
> Rob
> 


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