STEVAL-TCS003V1 STMicroelectronics, STEVAL-TCS003V1 Datasheet - Page 23

• Manufacturer Part Number: STEVAL-TCS003V1
• Description: BOARD DEMO EXPANDER STMPE2403
• Manufacturer: STMicroelectronics

Specifications of STEVAL-TCS003V1

• Main Purpose: Interface, GPIO Expander
• Embedded: No
• Utilized Ic / Part: STMPE2403
• Primary Attributes: 8/16/24-Bit 24-Port GPIO Expander over I2C
• Secondary Attributes: 3 8-Bit PWM Output for LEDs, Keyboard Matrix Scan, Special Key Support
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Other names: 497-8206

STMPE2403
8
8.1
Clocking system
Figure 5.
The decision on clocks is based on the bits written into SYSCON registers. Bits 0 to 4 of the
SYSCON register control the gating of clocks to the Rotator, Keypad Controller, PWM and
GPIO respectively in the operational mode.
Clock source
By default, when the STMPE2403 powers up, it derives a 32KHz clock from the internal RC
oscillator for it's operation. If external 32KHz crystal or clock source is available, it must be
configured to accept external clock through the SYSCON register.
In the case where the STMPE2403 is powered and configured to use external clock, and the
XTALIN is left floating, there will be an additional leakage current of approximately 20µA
drawn from the V
Clocking system
CC
.
Clocking system
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