MSDI MC33975 EVK and S32K118 EVK, Sleep Mode Switch Issue

cancel
Showing results for 
Show  only  | Search instead for 
Did you mean: 

MSDI MC33975 EVK and S32K118 EVK, Sleep Mode Switch Issue

1,274 Views
Learner
Contributor III

Hi 
I am interfacing MC33975 EVK with S32K118 EVK. 
I am able to get interrupt whenever switch status changed, and able to read the switch status as well.
But unfortunately i am not able to switch MSDI(MC33975) to sleep mode.
I am attaching the SPI connections diagram and the code that i am using for switching the mode of MSDI to SLEEP.
I am using USB power with 3.3v supply in S32K118 EVK.
SLEEP command i am using = 0x0C, 0x00,0x3F
Please suggest/recommend if anything if anything wrong.

Thanks

Learner_0-1629352944944.png

Learner_1-1629352968588.png

Learner_2-1629353197142.png

 

Tags (3)
0 Kudos
3 Replies

1,244 Views
reyes
NXP TechSupport
NXP TechSupport

Hi,

The 33975 device will exit the Normal mode and enter the Sleep mode only with a valid sleep command.

The sleep command contains settings for two programmable timers for Sleep mode, the interrupt timer and the scan timer, as shown in Table 18 of the datasheet.

 

The interrupt timer is used as a periodic wake-up timer. When the timer expires, an interrupt is generated and the device enters Normal mode. Note: The interrupt timer in the 33975 device may be disabled by programming the interrupt bits to logic [1 1 1].

 

The scan timer sets the polling period between input switch reads in Sleep mode. The period is set in the sleep command and may be set to 000 (no period) to 111 (64 ms).

 

For test purposes, please send the Sleep command as in Table 18, with the programming the interrupt bits to logic [1 1 1] (disabled) and sleep command [0 0 0] (no period). And check if the device goes into sleep mode.

 

 

The 33975 will exit Sleep mode and enter Normal mode when any of the following events occur:

  • Input switch change of state (when enabled)
  • Interrupt timer expire
  • Falling edge of WAKE
  • Falling edge of INT (with VDD = 5.0 V and WAKE at Logic [1])
  • Falling edge of CS (with VDD = 5.0 V)
  • Power-on reset (POR)

 

Make sure none of these are true to confirm the MC33975 is not getting into Sleep mode and exiting right away.

 

Regards,

Jose

0 Kudos

1,234 Views
Learner
Contributor III

Hi @reyes 
Thanks for your response with recommendations.

1. As per your recommendation, 

For test purposes, please send the Sleep command as in Table 18, with the programming the interrupt bits to logic [1 1 1] (disabled) and sleep command [0 0 0] (no period). And check if the device goes into sleep mode." 
 I have Send Sleep Command as 0x0C, 0x00, 0x38 (Interrupt Timer : Disabled, Scan Timer: No Scan)
But still i am not to to switch my EVK in to sleep Mode

2. As per your second recommendation, i have cross verified the following:

The 33975 will exit Sleep mode and enter Normal mode when any of the following events occur:

  • Input switch change of state (when enabled) : DISABLED
  • Interrupt timer expire: DISABLED
  • Falling edge of WAKE: WAKEUP PIN NOT CONNECTED TO S3K118
  • Falling edge of INT (with VDD = 5.0 V and WAKE at Logic [1]) : INT PIN USED AS INPUT AT S32k118
  • Falling edge of CS (with VDD = 5.0 V): NO SPI READING/WRITING AFTER SLEEP COMMAND.CS HIGH AFTER SENDING SLEEP COMMAND
  • Power-on reset (POR): NO POR AFTER SLEEP COMMAND

3.  Sequence of command for config:
RESET = 0x7F,0x00,0x00
PROGRAM SWITCH TO GROUND = 0x01,0x00,0x00
TRISTATE DISABLE - SP =0x09,0x00,0x00
TRISTATE DISABLE - SG =0x0A,0x00,0x00
SWITCH STATUS READ =0x00,0x00,0x00
SLEEP =0x0C,0x00,0x38

But unfortunately, still i am not able to switch EVK mode to sleep mode. 

QUESTION:
1. Is it mandatory to connect WAKE Pin to Microcontroller GPIO with Pullup?

0 Kudos

1,210 Views
reyes
NXP TechSupport
NXP TechSupport

Hi,

The WAKE pin has a passive pullup to the internal 5.0 V supply but may be pulled up through a resistor to VPWR supply (see Figure 17, page 27). When the WAKE output is not used the pin should be pulled up to the VDD supply through a resistor, as shown in Figure 16, page 27).

Regards,

Jose

0 Kudos