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K40: open drain not working

Question asked by Victor Martyshenko on Feb 26, 2012
Latest reply on Apr 5, 2012 by Markku Pulsa

I created a project using PE. GPIO outputs are initialized in an open-drain mode. When the output applied to the logic "1" output voltage is not more than 3.6 Volts. Outputs pulled up to 5V source voltage with 450 ohms resistor.
Status register PORTB_PCR19 after initialization:

 

PORTB_PCR19 = 120Pin Control Register nBit Field Values:      bits[ 31:25 ] = 0 ISF  bits[ 24:24 ] = 0 Configured interrupt has not been detected.      bits[ 23:20 ] = 0 IRQC bits[ 19:16 ] = 0 Interrupt/DMA Request disabled. LK   bits[ 15:15 ] = 0 Pin Control Register bits [15:0] are not locked.      bits[ 14:11 ] = 0 MUX  bits[ 10:8  ] = 1 Alternative 1 (GPIO).      bits[  7:7  ] = 0 DSE  bits[  6:6  ] = 0 Low drive strength is configured on the corresponding pin, if pin is configured as a digital output. ODE  bits[  5:5  ] = 1 Open Drain output is enabled on the corresponding pin, provided pin is configured as a digital output. PFE  bits[  4:4  ] = 0 Passive Input Filter is disabled on the corresponding pin.      bits[  3:3  ] = 0 SRE  bits[  2:2  ] = 0 Fast slew rate is configured on the corresponding pin, if pin is configured as a digital output. PE   bits[  1:1  ] = 0 Internal pull-up or pull-down resistor is not enabled on the corresponding pin. PS   bits[  0:0  ] = 0 Internal pull-down resistor is enabled on the corresponding pin, if the corresponding Port Pull Enable Register bit is set.

This is a hardware error? How to fix?


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