Re:Nice to have an Address and Data Bus
You can never have enough money or I/O. Many of the LMI chips have special function options available on the pins - seems a shame to under-use these for "lowly" I/O.
Assume an 8/16 bit D-Bus and 20 pin A-Bus - that could be 36 pins "plus" Control Strobes and Chip Selects. So we're up over 40 pins.
Now often there is the need for both "simple" requirements - where the micro's I/O is sufficient - and "complex" where the A-D Bus you reference is needed.
If you purchase the larger micro you will pay more, consume more space and likely STILL NOT have enough I/O. (as extra pins are dedicated to A-D Bus - not I/O)
Recognizing this my firm is closing on the introduction of a small, low cost IC which can address bulk memory (and more) and which "talks" to LMI via 8 bit parallel, SPI, I2C or Uart. (maybe CAN)
Intended for massive SRAM or Color TFT displays - you now can STAY with a smaller, more economical LMI micro - and use this "adjunct" IC as/if required. To simplify design-in we will offer a small pcb with our chip, 512KB SRAM + TFT drive.
Finally - routing 40+ traces from any micro to Memory or other "controllers" may be as much "art as science." Avoiding EMI will be a challenge. A custom IC - as we've described - not burdened with all of the "micro-innards" - allows short, optimal connections to bulk memory. Buying more of the smaller micro may earn you "next price break" savings - as well...
login or register to reply
|
