The content of this topic has been archived on 8 Apr 2018. There are no obvious gaps in this topic, but there may still be some posts missing at the end.
Some cpus support both types of memory - ddr1 and ddr2 (eg ar9331).
In the factory usually sets 32mb ddr1 and many users make mod to 64mb.
So why they does not change the type of memory to ddr2 at the same time?
Or changing the type of memory does not offer a performance boost -> does not make sense?
Or it is not possible at all?
PS If anybody has you-know-what for ar9341 - send it to my email, please.
(Last edited by kvartz on 12 Mar 2014, 10:07)
Doesn't DDR1 and DDR2 use different voltages, and thus the board circuitery is only prepared for only one type of RAM memory?
FYI They do make 64MB DDR1 Memory modules.
But there are five VDD_DDR cpu pins - "External memory power supply", and "VDD_DDR voltage is configured by the boot strap setting" (ar9331).
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BOOT_STRAP register, MEM_TYPR[13:12] bits: "Indicates external memory type; power on detection (GPIO12 and GPIO28)".
01 - DDR1
10 - DDR2
According to wr703 pinout, GPIO12 == 1 and GPIO28 == 0.
Does it mean, that during power-on process, voltage configures to safe low value (ddr2)?
Or there are reverse mapping [13:12] == [gpio28,gpio12] :/
(Last edited by kvartz on 13 Mar 2014, 09:20)
DDR1 and DDR2 has different packaging.
Generally, DDR2 usd BGA package.
The discussion might have continued from here.