All Forums
 BitsyX User's Manual
 Forum Locked  Topic Locked
 Send Topic to a Friend
 Printer Friendly
Author Topic  


296 Posts

Posted - 04 Apr 2003 :  16:00:24  Show Profile  Email Poster
BitsyX User's Manual ( PDF 796kB, power specs)

The BitsyX is a full-featured single board computer using the Intel PXA255 RISC microprocessor and SA-1111 Companion Chip. The BitsyX has the same form factor as the Bitsy Plus. Rev_1 BitsyX systems are functionally identical to rev_2 of the Bitsy Plus. See the last chapter of the manual for a list of differences between the BitsyX and the Bitsy Plus.

Changes, updates and errata for this document will appear as replies to this topic as they become available.

Related topics: BitsyX CE files page, Linux kernel downloads, ADSmartIO, mechanical drawings

Did you know?

You can get automatic email notifications when this, or any Topic is changed or replied to. Simply click the "Subscribe" icon () on the Topic, Forum, or Category list to subscribe. You can unsubscribe () just as quickly.

To cancel or manage subscriptions, click the "My Subscriptions" menu item at the upper right of any Forum page.

Edited by ctacke 5-May-2003: linked to Rev 2 manual
Edited by akidder 20-June-2003: updated to Rev 3 preliminary manual
Edited by akidder 22-July-2003: add links to CE and Linux files
Edited by akidder 10-Nov-2003: add links to ADSmartIO
Edited by akidder 2-Mar-2007: add power specs (Aug 2003)

Edited by - KnowledgeBase on 04 Apr 2003 16:02:57


877 Posts

Posted - 05 May 2003 :  11:23:11  Show Profile  Email Poster
Manual Update

The BitsyX had a number of internal changes between the Rev 1 and Rev 2 boards. We've posted a new User's Manual which better reflects these changes. Keep in mind that this is still a preliminary manual.
Go to Top of Page


1519 Posts

Posted - 09 Jun 2003 :  12:01:54  Show Profile  Email Poster
Addendum: J7 Mating Connector

Header J7 (XScale I/O signals) is 0.050-inch higher than the other headers on the board. If you are designing a personality board, use mating headers that are correspondingly shorter.

For example, if you used Samtec ESQT-125-02-F-D-500 elevated sockets for J3, J9 and J10, you would use ESQT-108-02-F-D-450 sockets for J7.
Go to Top of Page


1519 Posts

Posted - 20 Jun 2003 :  18:06:38  Show Profile  Email Poster
Manual Update

We've added more details about the I2C bus, voltage scaling, the J7 header, the XScale display signals and BitsyX production options. Download rev 3 of the manual from the link above!
Go to Top of Page


1519 Posts

Posted - 18 Sep 2003 :  13:29:02  Show Profile  Email Poster

Hardware Update: SA-1111 Interrupts

We've identified a condition under which the SA-1111 can violate the interrupt timing to the PXA255 XScale processor. The condition happens when an SA-1111 interrupt occurs while a pending SA-1111 interrupt is being serviced. The consequence is a processor lockup condition that cannot be prevented or resolved with software.

This condition occurs infrequently, but its likelihood is directly proportional to specific types of activity on the system. Statistically, we can't guarantee that this condition won't occur if more than one SA-1111 interrupt source is used in a system.

Interrupt sources from the SA-1111 include the following:
  • USB host (downstream) port


  • CompactFlash

  • Touch panel

  • Power failure interrupt

  • External interrupt 2 (EXT_IRQ2)

Resolution, Part 1: Hardware

We have successfully corrected this condition by adding a few rework wires to revision A BitsyX systems and updating the system controller firmware. The wires route the interrupt through a delay filter to keep the timing within spec. This rework is backward compatible with existing software, as it routes the SA-1111 interrupt along two separate paths.

The software updates below complete the fix.

All Rev A BitsyX systems shipped since September 15, 2003, include this rework. The rework connects to the EXT_IRQ3 input pin on the CPLD, so do not connect any external signals to EXT_IRQ3.

Rev 2 BitsyX systems do not require any rework (read on...).

Resolution, Part 2: Software

Rev A: To take advantage of the rework on rev. A systems, you must update the operating system:Rev 2: CE builds 4.10.28 and later include a software correction that does not require any rework to rev 2 boards.

For Further Information...

If you have questions about how this issue will affect your application, or would like to discuss returning your existing rev A BitsyX system for rework, please contact us.

Edited by akidder 30-Oct-2003: Add information about software fix for rev 2 BitsyX systems.
Edited by akidder 6-Nov-2003: Add information about not using EXT_IRQ3 on reworked rev A boards.

Go to Top of Page


1519 Posts

Posted - 29 Sep 2003 :  11:38:05  Show Profile  Email Poster

BitsyX rev A Changes

Revision A of the BitsyX has two minor changes over revision 2:


The SPI signals on J3 now connect to the XScale NSSP port; they are not shared with the touch panel controller as on rev 2.

The XScale NSSP port supports SPI, SSP, Microwire and PSP serial protocols. See Chapter 16 of the "Intel PXA255 Processor Developer's Manual" for details about the operation of the NSSP.

Reset Circuit Update

The reset circuit was updated. Rev 2 BitsyX systems sometimes did not reset when the reset signal was shorted to ground (rev 2 systems can be reworked with a new part to correct this issue).

Edited by akidder 1-Oct-2003: Add information about reset circuit update.
Edited by akidder 7-Oct-2003: Note that rev 2 reset circuit can be updated.
Edited by akidder 8-Jan-2004: Add diagram of rev A SSP layout.
Go to Top of Page


1519 Posts

Posted - 10 Nov 2003 :  16:16:33  Show Profile  Email Poster

Specification Change (Reworked Rev A Systems): Do not Connect to EXT_IRQ3

Do not connect any signals to BitsyX input EXT_IRQ3 (J10, pin 35) on Rev. A systems that have been reworked for the interrupt issue (above). The rework uses the CPLD port to which EXT_IRQ3 is connected. See above for details.

Please contact us if this specification change affects your application.
Go to Top of Page


1519 Posts

Posted - 10 Nov 2003 :  16:19:02  Show Profile  Email Poster
Rev 2 Bitsy X: Serial 3 Handshaking Lines

The CTS and RTS lines of serial port 3 may not be active on revision 2 BitsyX systems due to missing parts. If this issue affects your application, please let us know. We can update your system to enable these signals.
Go to Top of Page


1519 Posts

Posted - 10 Nov 2003 :  16:28:51  Show Profile  Email Poster

Some 3.3V PCMCIA Cards Cause System Reset

We have identified an issue under which the BitsyX resets when some 3.3-volt PCMCIA cards are inserted. This issue is due to the very high inrush currents of these cards (inrush current on one card peaked at 4.5A). This issue affects BitsyX revisions A and earlier.

If this issue affects your application, contact us to discuss available options. If you have designed your own BitsyX personality board, you can prevent this reset problem by adding capacitance to Vddx (see topic 408 for details). If you write us, please let us know the revision of your BitsyX and the brand/model of the PCMCIA/CF card that causes the issue
Go to Top of Page


1519 Posts

Posted - 02 Mar 2004 :  12:20:04  Show Profile  Email Poster

BitsyX I2C Components

If you plan to use I2C and are using a BitsyX system built before March 2004, you may need to update the BitsyX hardware. Use the following documents to determine if the recommended I2C components are installed on your system:
Locating the parts (GIF)
Schematic with part numbers (GIF)
In particular, we have recently updated the value of pull-up resistors R346 and R347 to meet the I2C specifications under a wider variety of conditions.

If you need to replace the I2C components on your BitsyX, please contact us with details about your I2C application.
Go to Top of Page


877 Posts

Posted - 22 Jun 2004 :  18:32:58  Show Profile  Email Poster

BitsyX GPIO33 and GPIO80

The BitsyX exposes two processor GPIOs on J7 (section 3.3.7 of the manual) which are available for use. In addition to general GPIO usage, you may also need to unmask the alternate function of GPIO80 as a chip select.

For an example of how to use these digital I/Os under Windows CE, see the BitsyXGPIO class found at Topic 1530.

These lines run directly to the processor with no electrical protection so use them with extreme caution; incorrect voltage or ESD through either one can easily damage the processor.

Go to Top of Page


1519 Posts

Posted - 23 Jun 2004 :  13:59:34  Show Profile  Email Poster

Erratum: Backlight PWM Voltage in Electrical Specification

The maximum voltage for "V backlightPWM" in section 6.2 of the BitsyX user manual electrical specifications is stated incorrectly. For BitsyX board revision 2 and later, the backlight PWM control voltage ranges from 0 to 5 volts, not 0 to 3.3V as listed.

This change is listed in the Revision History (chapter 7), but was not updated in the specifications.
Go to Top of Page


1519 Posts

Posted - 12 Nov 2004 :  15:37:51  Show Profile  Email Poster

Addendum: RL and UD resistors

Some displays support flipping the LCD display vertically and/or horizontally (see topic 485 for further details).

The RL and UD signals to the display can either be hard-wired in the display cable to the panel voltage(PNL_PWR) or ground, or they can be connected to the PNL_RL and PNL_UD signals.

The resistors for pull-up/down functionality on the BitsyX are UD:R79/R17 and RL:R87/R22, respectively. The standard BitsyX configuration populates the pull-up resistors. If you need to set one or both of these signals low, you can have us change the location of the resistors for your configuration.

The RL/UD resistors are in approximately the same location as on the Bitsy and Bitsy Plus. The following diagram shows details of where the resistors are located on the BitsyX, revision C:

Click image for detail.

Go to Top of Page


1519 Posts

Posted - 09 Jun 2005 :  17:28:06  Show Profile  Email Poster

Component Change: Surge Protection on EIO5

We will be removing the surge protection from the EIO5 digital I/O (J3 pin 12, PXA255 GP19) due to a mechanical interference issue. In some cases, this interference caused EIO5 to have low impedance to ground.

Since users typically don't interact directly with digital I/Os, we don't believe that this change will affect applications. Please contact us if you believe that this will affect your application.
Go to Top of Page


47 Posts

Posted - 12 Oct 2007 :  11:26:04  Show Profile
Erratum: VCON references

The BitsyX Users Manual Rev3:

On page 11 (section 3.3.1) "Zero to PNL_PWR volts". This should be replaced by the statement "VCON can range from 0 to VDDX with factory option".

On page 50 (section 6.2.2) Note 12 should include: "Only ranges to VDDX with factory hardware option. Otherwise ranges from 0 to 1.5V based on ADSmartIO PWM and the position of VR1 potentiometer."
Go to Top of Page
 Forum Locked  Topic Locked
 Send Topic to a Friend
 Printer Friendly
Jump To:
Eurotech Support Forums © Eurotech Inc. Go To Top Of Page
This page was generated in 0.06 seconds. Snitz Forums 2000