Interview Question - Gray Codes

What are the tradeoffs in implementing a program counter for a microprocessor using Gray coding?

Sol:

• Gray coding is designed to reduce power, because only one bit changes whenincrementing or decrementing.
• Program counters usually increment, rather than jump to completely different values.So, using gray coding should reduce power consumption.
• The downside is that the memory system probably doesn’t use gray-coded addresses,so additional circuitry would be needed to convert between gray andbinary codes. This will increase area and likely decrease performance.
• Additionally, the extra circuitry to do the translation might require more power than
  is saved by using gray coding.