# Smallest PIC which the TCP/IP stack can be implemented

What is the smallest (size) PIC with internal oscillator available which the TCP/IP stack can be implemented (and used) successfully? Also, what is the smallest (size) PIC with internal oscillator and Ethernet stack implemented?

• You should define your question little bit more. For example by smallest, do you mean smallest footprint, cheapest or you refer to amount of ram? – zzz Jan 22 '13 at 0:08

If you're going to use Microchip's TCP/IP Stack, the PIC18 is the 'lowest-end' family of PICs that the software stack supports.

On their Ethernet page, Microchip recommends the PIC18F97J60. It has MAC and 10BASE-T PHY integrated.

• IEEE 802.3 compatible Ethernet Controller
• Fully Compatible with 10/100/1000Base-T networks
• Integrated MAC and 10BASE-T PHY
• Up to 128KB Flash
• 8 KB Ethernet Buffer
• Support for Unicast, Multicast and Broadcast packets
• Programmable wake-up on multiple packet formats,including Magic Packet®, Unicast, Multicast, Broadcast,specific packet match or any
packet
• 64/80/100-Pin TQFP Package
• As far as I have seen both PIC18 and PIC32 families have the same minimum size, 10mm x 10mm x 1mm. Is there any other encapsulation with smaller size? – Frederico Schardong Jan 22 '13 at 0:23
• @Frederico So you're interested in the physical size of the chip (package). I couldn't say. – m.Alin Jan 22 '13 at 0:37
• The chip may have an internal oscillator, but I think you need an external 25MHz crystal to get the required clock for the Ethernet controller. – Robert Jan 22 '13 at 1:11
• @Robert that might be true but there is no sense put an internal oscillator that can't provide all the features that the microcontroller has – Frederico Schardong Jan 22 '13 at 2:57

You may want to explore the ENC28J60. It's an external chip from the PIC that handles all the Ethernet. It interfaces to the PIC via SPI bus. Just choose a PIC that has enough flash and RAM for the TCP/IP Stack. You can download and compile to a simulator to see how much space things take.

On the link provided by m.Alin you can see in the right bottom corner a button named See all Ethernet PIC MCUs which lead to here where you can see different characteristics, including packaging in the most right column. By the look of it, the smallest PIC32 with Ethernet are 64/QFN 64/TQFP

• I couldn't find any one smaller than 10 mm x 10 mm x 1 mm, am I missing something? – Frederico Schardong Jan 22 '13 at 2:54
• Not sure if it is any help, but 64QFN have 9x9x0,9 mm. Albeit 10% shorter side it is still only a 1 mm difference and I have a feeling you looking for something much smaller. – zzz Jan 22 '13 at 6:00
• as small as possible. I found the ENC28J60 which has a 5.3 mm of length and other encapsulations with 6x6 mm. I just don't know exactly what I can do with them, I mean, I just need ethernet, I don't need any other functionality of a PIC, so maybe that's the smallest CI I can find – Frederico Schardong Jan 22 '13 at 6:16