AM335x OPP50 v. OPP100

Srinivasan Rajan89

Other Parts Discussed in Thread: AM3357

Hi,

I'm using AM3357. For this processor VDD_CORE and VDD_MPU mentioned 1.1 Volt. But its very depends on OPP50 and OPP100. What is OPP (Operation Performance Point). And how it related with Operating voltage.

over 9 years ago

0 Biser Gatchev-XID over 9 years ago

TI__Guru**** 393215 points

Please see section 5.4 in the AM335x Datasheet Rev. J.

0 Srinivasan Rajan89 over 9 years ago in reply to Biser Gatchev-XID

Prodigy 100 points

From same section only i got doubt. may i know basic idea about OPP( Operating Performance Point). And my processor maximum support frequency is 800Mhz. Then what is my VDD_Core and VDD_MPU how to find it.

0 Biser Gatchev-XID over 9 years ago in reply to Srinivasan Rajan89

TI__Guru**** 393215 points

What is your processor exact part number?

0 Srinivasan Rajan89 over 9 years ago in reply to Biser Gatchev-XID

Prodigy 100 points

AM3357BZCZA80

0 Biser Gatchev-XID over 9 years ago in reply to Srinivasan Rajan89

TI__Guru**** 393215 points

OK, so this is silicon revision 2.1 at 800MHz. The following tables from the AM335x Datasheet Rev. J apply for this device:
Table 5-6 for CORE OPPs
Table 5-7 for MPU OPPs
Table 5-8 for valid combinations of CORE and MPU OPPs

As you can see the maximum MPU OPP for this 800MHz device is Turbo. Normally CORE/MPU OPP50 is used only for designs with very low processing requirements that also require maximum power savings. Normally Core is set at OPP100 and MPU can be from MPU100 to Turbo. You can see from the tables that MPU OPP on the maximum MPU frequency that can be used, while CORE OPP influences the DDR and L3/L4 interconnect frequencies.

Linux manages the OPPs via the power management techniques employed. See this wiki for details: processors.wiki.ti.com/.../Linux_Core_Power_Management_User's_Guide_(v4.1)

Note that to be able to use the dynamic power management techniques your design must use one of the recommended PMICs for AM335x: processors.wiki.ti.com/.../AM335x_Hardware_Design_Guide

0 cobsonchael over 8 years ago in reply to Biser Gatchev-XID

Mastermind 7930 points

so i just want to piggyback on this and ask a simple question about OPP (which is what i think Srinivasan Rajan89 was asking to begin with)

is the OPP determined by the voltage present at boot time? if not, how is OPP set?

0 Pavel Botev over 8 years ago in reply to cobsonchael

TI__Guru**** 170625 points

Hi Cobsonchael,

The OPP is combination of frequency and voltage. When you set your board VDD_MPU voltage at 1.26V (OPP Turbo) during boot, the MPU frequency will not be set at 800MHz automatically.

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AM335x OPP50 v. OPP100