ROM – Experimental Engineering

Posted on November 20, 2016November 17, 2016 by The Engineer — Leave a comment

Behringer DEQ2496 Mastering Processor

I was recently given this unit, along with another Behringer sound processor to repair, as the units were both displaying booting problems. This first one is a rather swish Mastering Processor, which has many features I’ll leave to Behringer to explain 😉

All the inputs are on the back of this 19″ rackmount bit of kit, nothing much on this PCB other than the connectors & a couple of switching relays.

All the magic is done on the main processor PCB, which is host to 3 Analog Devices DSP processors:

ADSP-BF531 BlackFin DSP. This one is probably handling most of the audio processing, as it’s the most powerful DSP onboard at 600Mhz. There’s a ROM on board above this for the firmware & a single RAM chip. On the right are a pair of ADSP-21065 DSP processors at a lower clock rate of 66MHz. To the left is some glue logic to interface the user controls & dot-matrix LCD.

The PSU in this unit is a pretty standard looking SMPS, with some extra noise filtering & shielding. The main transformer is underneath the mu-metal shield in the centre of the board.

Posted on February 17, 2016 by The Engineer — Leave a comment

IC Decap: Motorola MC68HC11E9 8-Bit Microcontroller

This particular IC came out of a very old VHF band radio, from the early 90’s. The die was encased in a custom ceramic package, like every other IC in the radio, with a custom part number. I managed to identify it from the markings on the silicon.

This was a pretty powerful MCU for it’s time, with 16K of onboard ROM, 512 bytes of both RAM & EEPROM, a 16-bit timer, 8-bit ADC, SPI & a MC68HC11 CPU core.

Posted on October 21, 2012October 21, 2012 by The Engineer — Leave a comment

Routemaster Control Unit

This is the control unit for a Routemaster system, that downloads traffic information for the area local to the vehicle.

Here is an overview of the unit, in it’s aluminium box.

Here is the unit with the top cover removed, showing the pair of PCBs. The bottom PCB is the main control PCB, the top one holds an IC similar to a SIM card & part of the radio.

Here is the main PCB removed from the casing, contains the program ROM & microcontroller. for the system

Daughtercard view. This holds another programmed CPLD, the custom SIM-like IC & the RTC battery, along with some power conversion circuitry.

This is the radio receiver, looks to be AM, the large loop antenna can be seen at the bottom of the box.