800MHz working ? on AM3874EVM

Hi,

I have one more question.

If AM3874ES device can work with 800MHz frequency, Ithink it is needed to change PMIC configuration.

Because PMIC(TPS659113) supplys 1.2V VDD to ARM Core. However, as you know, AM3874 must be

supplied 1.35V VDD for working with OPP166.

How should I modify PMIC's configuration? Also, is there other portion I should modify in EVM for 800MHz

working?

I appreciate your quick reply.

Best regards,

Michi

Michi,

Michi Yama said:

I have one AM387x EVM. And there is an AM3874 on EVM.

The marking of its device is the below.

-------------------------------

X8148X3874BCYE

162EXD9

662        CYE

-------------------------------

This is actually the DM8148 EVM, which has DM8148 processor and emulates AM3874 processor:

http://www.ti.com/tool/tmdxevm8148

DM8148 Processor (emulates AM3874)

My own DM8148 EVM has the below labels:

X8148X3874BCYEF
15AJL7C

Michi Yama said:

Does this device wok with 800MHz or 1GHz?

As you have CYE device, according to the DM814x datasheet, this is up to 600MHz ARM:

DEVICE SPEED RANGE
Blank = 600-MHz ARM, 500-MHz DSP
0 = 720-MHz ARM, 600-MHz DSP
1 = 1000-MHz ARM, 700-MHZ DSP
1 = 1000-MHz ARM, 750-MHZ DSP [SR3.0 only]
2 = 1000-MHz ARM, 750-MHz DSP

CYE0 device is up to 720MHz ARM, CYE1 is up to 1000MHz ARM and CYE2 is up to 1000MHz ARM.

Michi Yama said:

Does this device wok with 800MHz or 1GHz?

I think it is up to 600MHz, as you have CYE device (not CYE0, CYE1, or CYE2).

But I have CYEF device which is up to 1000MHz.

So, I will double check with Mistral (the EVM manufacture) what is the max ARM frequency of your specific EVM, if it is 600MHz or higher. I will let you know their feedback.

Best regards,
Pavel

Michi,

Michi Yama said:

Because PMIC(TPS659113) supplys 1.2V VDD to ARM Core. However, as you know, AM3874 must be

supplied 1.35V VDD for working with OPP166.

How should I modify PMIC's configuration?

You should use the I2C interface to set the PMIC. See the below e2e thread for more info:

http://e2e.ti.com/support/dsp/davinci_digital_media_processors/f/716/t/204555.aspx

Dear Pavel-san,

Thank you for your support.

I have one more question.

> i2c mw  0x2D 0x22 0x3C

i2C mw : I2C memory write

0x2D : the address of TPS659113 on I2C

0x22 : the address for the register of TPS659113. It is VDD1_OP_REG register.

0x3C : the value of VDD1_OP_REG register.

Is the above my understanding right?

If it is so,  I have one quesion. According to the datasheet of TPS659113, the value "0x3C" is not for 1.35V output. It should be "0x3F". For OPP166, AM3874 CORE ARM voltage is need to be supplied 1.35V. Why "0x3C" is used, not "0x3F"?

Please advise me.

I appreciate your quick reply.

Best regards,

Michi 

Michi,

Michi Yama said:

Is the above my understanding right?

Right

Michi Yama said:

If it is so,  I have one quesion. According to the datasheet of TPS659113, the value "0x3C" is not for 1.35V output. It should be "0x3F". For OPP166, AM3874 CORE ARM voltage is need to be supplied 1.35V. Why "0x3C" is used, not "0x3F"?

All the values between 0x3C and 0x3F (0x3C, 0x3D, 0x3E, 0x3F) works fine for setting the voltage to OPP166/1.35V. I have just tested these values on my DM8148/AM3874 EVM, and it works fine.

From my point of view, 0x3C and 0x3F values has exactly the same effect. You can use the 0x3F value to be fully aligned with the TPS659113 datasheet, I do not see any issue in this.

You can also double check this in our PMU TPS659xx PMIC dedicated forum:

http://e2e.ti.com/support/power_management/pmu/f/43.aspx

BR
Pavel