[LS1046ARDB] Inquiries regarding CPLD, Temp monitor/sensor and 1588

[heesoo_ahn]

To whom may it concern

Hello, I'm HS.

I've been designing the board referenced from LS1046ARDB.

Please refer to following questions and answer as detailed as possible.

1. CPLD

According to LS1046ARDBRM, CPLD is used for various features such as power on/off, and reset sequence, DDR Reset signal etc.

I'm wondering if i replace the CPLD with another analog/digital IC like power sequencer.

CPLDs seemed to be used for many options, but there are some features i don't use such as rtc clock.

So I would appreciate if you clarify essential features of CPLD and confirm that if it is replaceable.

2. Temp monitor/sensor.

There are two ways to read junction temperature of LS1046A: 5 internal temp sensors and internal diode with temperature monitor(ADT7461).

Why do LS1046ARDB use two ways to read junction temperature?

Is it possible that shutting down LS1046A using the data from 5 internal temp sensors which would be read by registers?

I assume that an internal temp diode and a temp monitor(ADT7461, On semiconductor) are used for thermal shutdown when the T_J is higher than programmed threshold value.

The application i have been working on doesn't need fans.

Please check if my assumption is right and confirm if the temp monitor is necessary or not.

3. 1588

I would appreciate if you describe the 1588 test header pins in LS1046ARDB.

I checked the table below though it wasn't as detailed as i want..

Especially, I'm wondering how TMR_TRG[1:2] can be used.

4. IRQ block of LS1046A

I couldn't find the information of  IRQ[00:11] 

Please explain how IRQ[00:11] are used.

Thank you

[r8070z · Accepted solution]

1) CPLD is not mandatory. It just simplifies implementation of the reference board which should cover many use cases. Chapter 3 “CPLD Specification” of QorIQ LS1046A Reference Design Board Reference Manual covers all CPLD functions. In the simplest case you can replace it by another analog/digital IC like power sequencer and reset generator.

2) The TMU has access to multiple temperature measurement sites strategically located on the chip. It monitors these sites and can signal an alarm if a programmed threshold is ever exceeded. The upper and lower temperature range is continuously captured. A set of reporting registers allow for reading the current temperature at monitored sites. However it is software depended. The temperature diode can be used to monitor its temperature by using some external temperature monitoring devices and do not require proper software. In any case you as system designer decide how you will use that opportunities. 

3) You can find these details in chapter 7 “IEEE 1588 Timer Module” of QorIQ LS1046A Data Path Acceleration Architecture (DPAA) Reference Manual. Shortly trigger edge on the trig input causes the appropriate TMR_ETTSn_H/L register to be updated with a time-stamp value and generate timer event.

4) IRQ0-11 are external IO signals connected to the LS1046A interrupt controller (GIC-400). The external IO signals (IRQ0-11) are directly connected to interrupt lines and hence the status of these interrupts are available in the corresponding GIC-400 registers