From c1ea9359339033fa0e52a8b8122d1fdd3e405522 Mon Sep 17 00:00:00 2001 From: Jet Hughes Date: Sat, 23 Jul 2022 23:04:14 +1200 Subject: [PATCH] vault backup: 2022-07-23 23:04:14 --- content/notes/04-computer-architecture.md | 39 ++++++++++++++++++++++- 1 file changed, 38 insertions(+), 1 deletion(-) diff --git a/content/notes/04-computer-architecture.md b/content/notes/04-computer-architecture.md index 5134f619e..ad1cac632 100644 --- a/content/notes/04-computer-architecture.md +++ b/content/notes/04-computer-architecture.md @@ -7,7 +7,44 @@ tags: - tristate buffer [slide](https://i.imgur.com/2Kb419g.png) -- ![memory write](https://i.imgur.com/PExnbFm.png) +- ![memory write](https://i.imgur.com/PExnbFm.png) [circuit simulator](https://tinyurl.com/2bmqovqz) - ![memory read](https://i.imgur.com/GZwxuaA.png) +# Bus +- data bus +- address bus +- control bus +- conmmunicate between parts of the computer +- only one transmitter at a time +- only addressed device can respond +- 2 levels + - internal + - external + +# Memory +- memory size is dependent on bus size + - 2n bytes for n-lines on the address bus + - 2^8=256B, 2^16=64KB, 2^32=4GB, 2^64=16EB + +- flip flops are grouped into bytes (or larger) + - each byte has an address + - to write + - present the address and the data + - tell chip to write + - to read + - present the address + - tell the chip to read + - look at the data + +## Static RAM (SRAM) +- memory made from flip flops is called static RAM + - used mostly in CPU cache + - or anywhere where only a small amount is needed + - expensive + +## Dynamic RAM (DRAM) +- made from capacitors +- used where large amount of RAM is needed +- slower than SRAM +- inexpensive \ No newline at end of file