Underclocking ARM and SRAM

Started by ghazanhaider in comp.arch.embedded13 years ago 14 replies

I have an LPC3180 header board that needs 10MHz+ crystals to run per spec. I plugged in a ~2MHz crystal and it ran, as slow as expected. I've...

I have an LPC3180 header board that needs 10MHz+ crystals to run per spec. I plugged in a ~2MHz crystal and it ran, as slow as expected. I've underclocked PIC parts down to being static, even using a button as a clock. Can this be done with ARM MCUs? Can this be done with ARM MCUs interfaced with SRAM chips?


LAN91C111Internal PHY

Started by Ted Wood in comp.arch.embedded15 years ago 4 replies

We're having a problem getting the SMSC LAN91C111 to work on one of our ColdFire boards. We can access memory-mapped MAC registers, but we can't...

We're having a problem getting the SMSC LAN91C111 to work on one of our ColdFire boards. We can access memory-mapped MAC registers, but we can't get the serial Management Interface to the PHY to work. Selecting the external PHY connection to break our MI signals out, everything looks fine on the scope, right number of clock pulses etc., etc. Am I missing something obvious? Cheers TW


Somewhat OT: Efficient timing under Linux

Started by Bruce Varley in comp.arch.embedded7 years ago 5 replies

Programming a somewhat compute-intensive and time-critical application on an embedded ARM-9 system, running Linux. I need a clock in the low...

Programming a somewhat compute-intensive and time-critical application on an embedded ARM-9 system, running Linux. I need a clock in the low tens of milliseconds for triggering synchronous functions, ie. while (1) { if Timeout (say 30mS) { reset timer do some stuff } } The standard Linux itimer functions and callback mechanism will s...


UTOPIA interface signal traces

Started by Nithin in comp.arch.embedded14 years ago 2 replies

Hi I am new to UTOPIA interface. I would like to know how critical it is to have matched lengths for UTOPIA data and clock traces on PCB...

Hi I am new to UTOPIA interface. I would like to know how critical it is to have matched lengths for UTOPIA data and clock traces on PCB with multiple processers (all processer having UTOPIA interface). It would be nice if somebody could reply as soon as possible. Regards Nithin


Help with this PIC code

Started by eryer in comp.arch.embedded9 years ago 2 replies

Hi, i want your opinion about this code for PIC24FJ32GB002...I want to use internal FRC for bus clock at 8MHz and obtain a PWM output...

Hi, i want your opinion about this code for PIC24FJ32GB002...I want to use internal FRC for bus clock at 8MHz and obtain a PWM output at 150KHz...this is my first pic code and i can't test it (i haven't any evalboard)...what do you think? This is my code #include #define DEBUG _CONFIG2(IESO_OFF & FNOSC_FRC & POSCMOD_NONE) _CONFIG1(JTAGEN_OFF & ICS_PGx2 & FWDTEN_OFF


Need advices about possible ICE protocol

Started by Daniele C. in comp.arch.embedded13 years ago 4 replies

Hi there, we have an ICE subsytem with the following pins: - CK (clock) - DO (data out) - DI (data in) - EN- (enable) - RST-...

Hi there, we have an ICE subsytem with the following pins: - CK (clock) - DO (data out) - DI (data in) - EN- (enable) - RST- (reset) The text in parentheses is our forecast meaning of the pin, while the uppercase acronyms are their names as reported in the (few) technical notes we have. Each pin has the "ICE" prefix, so we know this is a generic In-Circuit Emulator. The datashee...


Chipcon/8051 sanity check

Started by FreeRTOS.org in comp.arch.embedded12 years ago 18 replies

Hi, I have a problem with a timer interrupt on a CC1110 (8051 with wireless interface) that I have been staring at for an hour with no...

Hi, I have a problem with a timer interrupt on a CC1110 (8051 with wireless interface) that I have been staring at for an hour with no success. 8051 is not a strength of mine so I would appreciate your comments - Given the (very!) simple program: char x; int main( void ) { char c = 0; ____IEN0 &= ~pdBIT_7; ____SetClockSource(); // Setup processor clock. ____vInitTimer3( 100...


what can i do with those gpio ?

Started by RusH in comp.arch.embedded15 years ago 9 replies

I'v got a mips SoC running Linux kernel, 16(maybe 32 if i sacrifice some memory) GPIO pins sitting bored (16 can initiate interrupt). There is...

I'v got a mips SoC running Linux kernel, 16(maybe 32 if i sacrifice some memory) GPIO pins sitting bored (16 can initiate interrupt). There is also UART port (22MHz clock = very fast, 40ns cycles). I'm evaluating my options about using them : -IDE/CF interface -SD/MMC interfase ? -Camera -LPT (printserver) -USB host controller ? -... ? I would love to see such a project with a sam...


Capture 10 sec with 25 MSamples/s (4 - 8 Bits)... how to do ?

Started by Martin Maurer in comp.arch.embedded13 years ago 13 replies

Hello, i am in the need to capture around 10 seconds (ok, 5 to 8 seconds would also be enough) with 25 MSamples / s. Each sample should be 4...

Hello, i am in the need to capture around 10 seconds (ok, 5 to 8 seconds would also be enough) with 25 MSamples / s. Each sample should be 4 to 8 digital lines. It would be nice if i can use an external clock. But how to do this ? The amount of data for 10s * 25 MSamples / s * 1 Byte = 250 MByte. So it is not a small amount !?! So at the moment i have 3 ideas to solve this: 1) FPG...


18F452 RC oscillator mode

Started by SebastiaNot in comp.arch.embedded11 years ago 7 replies

I read in ( 18Fxx2 DataSheet ) > > > http://ww1.microchip.com/downloads/en/DeviceDoc/39564c.pdf that I can use a Resistor and a...

I read in ( 18Fxx2 DataSheet ) > > > http://ww1.microchip.com/downloads/en/DeviceDoc/39564c.pdf that I can use a Resistor and a Capacitor to clock the 18f452 PIC Page 18 says (including a diagram) : Recommended values:3 k=A6=B8 =A1=DC REXT =A1=DC 100, CEXT > 20pF But there is not place I can find the achieved clocking related to those values. Any clue ? Sebastian.


ATmega8515 power consumption

Started by Meindert Sprang in comp.arch.embedded14 years ago 16 replies

I am struggling to get the power consumption of sensor device down. According to the datasheet (page 208, top graph), the ATmega8515 I use,...

I am struggling to get the power consumption of sensor device down. According to the datasheet (page 208, top graph), the ATmega8515 I use, uses slightly less than 1mA @ 3.3V and 1MHz internal clock while active. But I measure around 2.3mA. Even when I stop all I/O and go into an endless loop, it still uses 2.1mA. Is Atmel showing off here or am I missing something? Meindert


clock synchronization over IP

Started by Anonymous in comp.arch.embedded12 months ago 36 replies

We need to synchronize clocks (so we can synchronize audio) on physically separated controllers that are connected via ethernet that may or may...

We need to synchronize clocks (so we can synchronize audio) on physically separated controllers that are connected via ethernet that may or may not be connected to the internet. The controllers have ARM9 LPC3250 SOM and embedded Linux. We need to synch with no more than 50 ms difference but preferably less. Synchronization needs to continue working between any two controllers reg


EDK =>"Virtex4_PPC_Example_9_1" on ubuntu, not able to change LEDs blinking through minicom hyperterminal

Started by N.V. Chandramouli in comp.arch.embedded12 years ago

hi, we are trying to run the "Virtex4_PPC_Example_9_1" example program (that came along with the EDK9.1.2 kit) that has TestInterrupt.c routine...

hi, we are trying to run the "Virtex4_PPC_Example_9_1" example program (that came along with the EDK9.1.2 kit) that has TestInterrupt.c routine (timer interrupt driving the LEDs and UART interface displaying the status.) "We are able to see LEDs flashing on the board but not able to speed up or slow down the clock using the 'f' , 's' inputs through the hyperterminal, which we are expecte...


interfacing cpld

Started by Justas P in comp.arch.embedded10 years ago 9 replies

Hi there, a newbie question, and I would be grateful for a response or at least hint where to look(read) for information. My problem is: I...

Hi there, a newbie question, and I would be grateful for a response or at least hint where to look(read) for information. My problem is: I have two synchronisation domains. One device (A) is running at a 2.048 frequency. Then there is a STM32 microcontroller (B) that is using 8 MHz clock source. Dev A gives out NRZ data stream and accept NRZ data stream. I want to send and receive data ...


Need help with Netburner SB72IO timing interface

Started by eric in comp.arch.embedded15 years ago 1 reply

This is a multi-part message in MIME format. ------=_NextPart_000_000B_01C4D617.32223130 Content-Type:...

This is a multi-part message in MIME format. ------=_NextPart_000_000B_01C4D617.32223130 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable We plan on using a GPS PPS signal that will be used to update the = internal clock on each net burner (one for each application/sensor). One = issue we are currently trying to resolve is how best to handle th...


LauterBach ICD - TRACE32 for MIPS4k

Started by mayureshsawant81 in comp.arch.embedded13 years ago 1 reply

Hi all, I have 4 boards, on one board lauterbach GUI is stable (flash contents)- it is not running. But on other three boards it is jumping. So...

Hi all, I have 4 boards, on one board lauterbach GUI is stable (flash contents)- it is not running. But on other three boards it is jumping. So my client says, the boards are ok, b'caz they are also use the same boards. So I dont understand what is the problem? Is this really lauterbach issue? And one more every board runs on differen Ejtag clock freq (10,25 or 5 Mhz) Please help.... R...


RTC PCF8563: Does not count

Started by Thomas Entner in comp.arch.embedded12 years ago 1 reply

Hello, I am using the PCF8563 as RTC on my board. It should be plain simple to access via I?C. Other people seem to use it without problems,...

Hello, I am using the PCF8563 as RTC on my board. It should be plain simple to access via I?C. Other people seem to use it without problems, therefore following problem is driving me nuts: I can read and write the registers in the part via I?C. The clock is running at its 32.768kHz. I can set a date and read it back. However: The RTC does not count correctly?!? I observed following: ...


trouble with logic counters

Started by panfilero in comp.arch.embedded13 years ago 5 replies

Hello, I'm trying to hook up a 74HCT163 to count from 0 to 7 then loop and keep doing it. I'm having a lot of trouble making sense of the data...

Hello, I'm trying to hook up a 74HCT163 to count from 0 to 7 then loop and keep doing it. I'm having a lot of trouble making sense of the data sheet on how to connect this thing. I have a 555 chip creating my clock, it's lighting an LED right now, I took that from the positive end of the LED and am running it into the counter. I was worried about going straight from the 555 chip to the cou...


AVR with Parallel Flash Memory

Started by NMMX in comp.arch.embedded9 years ago 12 replies

Hi all, I have a few questions on how to go about generate the correct waveforms for reading/writing from/to an external flash memory using an...

Hi all, I have a few questions on how to go about generate the correct waveforms for reading/writing from/to an external flash memory using an AVR microcontroller. The AVR has enough I/O to allow direct connection between address, data and control lines. I don't have to worry about counters/latches etc. The AVR is using a 12MHz clock. How do you work out how long each cycle will take? ...


ADS1251 and 8051 Code

Started by Bill Davy in comp.arch.embedded10 years ago 12 replies

ADS1251 and 8051 Code Has anyone done this who can share the code? Just to save me time. Any gotchas? I'd also quite like...

ADS1251 and 8051 Code Has anyone done this who can share the code? Just to save me time. Any gotchas? I'd also quite like not to take every sample so I can use just the ADS1251 to interrupt so it is both my clock and a data ready interrupt. I suppose it would be best to at least take one bit of the result. TIA, Bill