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Spinneret datasheet question/read pointer? — Parallax Forums

Spinneret datasheet question/read pointer?

AKruzelAKruzel Posts: 25
edited 2011-08-04 04:55 in Accessories
Hello all,

I'm just starting out with the spinneret and have been reading the datasheet and have stumbled on something that i'm trying to understand but i'm not sure if it's just one of those things we just follow the datasheet on and don't question. I'm refering to the Sn_RX_RD register which is the Socket n Read Pointer Register. It's supposed to point to the location to read receiving data but it even says in the datasheet, "the value itself is not the physical address to read" and it goes on to give you calculations to do to figure out the actual physical location. Why doesn't this pointer just provide the physical location and call it a day? For example on page 35 for transmitting data, the datasheet has an example at the top right hand corner that S0_TX_WR = 0X8FEE (granted this is the TX write pointer register but the physical address for transmitting looks to be calculated the same way). From what i see on the datasheet, this register shouldn't even exist because on sheet 14 of the datasheet, the upper end of the memory map is at 0x8000 and this would be RX memory. It appears to me like this pointer register gives us some arbitrary value that we need to decode to find the get the physical address. With how intelligent this chip is, i'm curious as to why they don't just give us the physical address and there may be a point to this arbitrary value.

Perhaps i'm just looking WAY too much into this.

Thanks
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