1 BCM datasheet errata. the BCM Broadcom specifies the reserved bits the other way around: “Write zeroes, read: don’t care”. Read about ‘Broadcom: Datasheet for BCM ARM Peripherals’ on element14 .com. Broadcom: Datasheet for BCM ARM Peripherals. If you have been following Raspberry Pi project, you may have noticed the dearth of documentation related to Broadcom processors.

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The CDIV value is documented as “must be a power of 2″. Retrieved from ” https: The I2C section on page 34 mentions MHz as a “nominal core clock”.

The IO register is documented as 0x7ea0 with automatic deassert and 0x7eb0, whereas the table eatasheet page 8 shows 0x7e The table, legend for tablestarted on page shows twice in red: I think- not confirmed. If 1 the receiver shift register is NOT cleared. I strongly suspect that the CDIV counter is only 14 bits wide.

The Peek register is documented here as being at 0x7ec, whereas the table on page 8 shows 0x7e There is amiguity on what register bits can be modified while the Briadcom system is active. They should both read “If this bit cleared no new symbols will be This does not match the diagram on page – which shows this function is selected with alternative function 4. This is confusing as indeed there is a different module called SPI0 documented on page and onwards.

This had lead to a confusing picture.

The hardware was changed detecting “half full” was difficult? This is from Geert Van Loos at the page below:. There is a space in ” full ” that would hint at that the word “half” was taken away. Switch on option for linking, so cross-references and dayasheet of contents can be jumped through.


Possibly the “choice” hasn’t been specified. Views Read View source View history. In table the values in columns “min output freq” and “max output bcm2385 should be in each others. An easy implementation would implement the 0 value as the maximum divisor.

BCM2835 datasheet errata

You must write the MS 8 bits as 0x5A. Many datasheets specify “write: Thus new data is concatenated to old data. Privacy policy About eLinux.

It looks like it contains the information that programmers need. However, bits 7 and 9 does not match the original datasheet, nor my guess The quality of the datasheet is high.

BCM datasheet errata –

How do these combine??? There is a bug in the I2C master that it does not support clock stretching at arbitrary points. I dunno the official answer to this, but the community-written SPI drivers here and here set them both at the same time.

Link to it via two control blocks on broadco primary chain.

Under rare situations this may result in “lost” clocks while MOSI still shifts out the data! Some of datashdet tables from the datasheet have been reproduced here. Not as “half the maximum”. Broadcom specifies the reserved bits the other way around: However the exact speed of the APB datashest is never explained. A detailed analysis of this bug can be found at http: That is the values in column “min output freq” are the maximum output frequency values and the values in column “max output freq” are the minimum output frequency values [check: Near the bottom of the page RXR.


This is not true. UART 1 should be: The bottom bit doesn’t work as per specifications, and because the “0” results inthe top bit doesn’t either. Another hint is that it says that the bit clears when “sufficient” data is read from the FIFO. The divider is split between an integer divider and a fractional mashing divider.

This page was last edited on 9 Julyat broascom If 0 the receiver shift register is cleared before each transaction. Allusions to the APB clock domain are made. And by specifying “read: Brosdcom register reads as 0x after reset. If you expand the hardware the hardware may be enhanced and do “different things” if you write ones to the previously “reserved” bits. The second block, with functions starting: Introduction This test application is intended to present a simple to understand user space test application that can be used to control the output of the Bc2m835 PI I2S bus.

Raspberry Pi Releases BCM2835 Datasheet for ARM Peripherals

This may happen every time this bit is set, but it is not measurable every time when sampling at 16MHz higher sampling speeds would be needed to confirm that. It also “does the right thing” with reserved bits. Does this mean, that the SYNC bit can also be changed at runtime as well?