4000S Datasheet, PDF (6/35 Pages) Cypress Semiconductor – 32-bit MCU Subsystem

PSoC^® 4: PSoC 4000S
Family Datasheet
GPIO
The PSoC 4000S has up to 36 GPIOs. The GPIO block imple-
ments the following:
■ Eight drive modes:
❐ Analog input mode (input and output buffers disabled)
❐ Input only
❐ Weak pull-up with strong pull-down
❐ Strong pull-up with weak pull-down
❐ Open drain with strong pull-down
❐ Open drain with strong pull-up
❐ Strong pull-up with strong pull-down
❐ Weak pull-up with weak pull-down
■ Input threshold select (CMOS or LVTTL).
■ Individual control of input and output buffer enabling/disabling
in addition to the drive strength modes
■ Selectable slew rates for dV/dt related noise control to improve
EMI
The pins are organized in logical entities called ports, which are
8-bit in width (less for Ports 2 and 3). During power-on and reset,
the blocks are forced to the disable state so as not to crowbar
any inputs and/or cause excess turn-on current. A multiplexing
network known as a high-speed I/O matrix is used to multiplex
between various signals that may connect to an I/O pin.
Data output and pin state registers store, respectively, the values
to be driven on the pins and the states of the pins themselves.
Every I/O pin can generate an interrupt if so enabled and each
I/O port has an interrupt request (IRQ) and interrupt service
routine (ISR) vector associated with it (5 for PSoC 4000S).
Special Function Peripherals
CapSense
CapSense is supported in the PSoC 4000S through a CapSense
Sigma-Delta (CSD) block that can be connected to any pins
through an analog multiplex bus via analog switches. CapSense
function can thus be provided on any available pin or group of
pins in a system under software control. A PSoC Creator
component is provided for the CapSense block to make it easy
for the user.
Shield voltage can be driven on another analog multiplex bus to
provide water-tolerance capability. Water tolerance is provided
by driving the shield electrode in phase with the sense electrode
to keep the shield capacitance from attenuating the sensed
input. Proximity sensing can also be implemented.
The CapSense block has two IDACs, which can be used for
general purposes if CapSense is not being used (both IDACs are
available in that case) or if CapSense is used without water
tolerance (one IDAC is available).
The CapSense block also provides a 10-bit Slope ADC function,
which can be used in conjunction with the CapSense function.
The CapSense block is an advanced, low-noise, programmable
block with programmable voltage references and current source
ranges for improved sensitivity and flexibility. It can also use an
external reference voltage. It has a full-wave CSD mode that
alternates sensing to VDDA and Ground to null out power-supply
related noise.
LCD Segment Drive
The PSoC 4000S has an LCD controller, which can drive up to
8 commons and up to 28 segments. It uses full digital methods
to drive the LCD segments requiring no generation of internal
LCD voltages. The two methods used are referred to as Digital
Correlation and PWM. Digital Correlation pertains to modulating
the frequency and drive levels of the common and segment
signals to generate the highest RMS voltage across a segment
to light it up or to keep the RMS signal to zero. This method is
good for STN displays but may result in reduced contrast with TN
(cheaper) displays. PWM pertains to driving the panel with PWM
signals to effectively use the capacitance of the panel to provide
the integration of the modulated pulse-width to generate the
desired LCD voltage. This method results in higher power
consumption but can result in better results when driving TN
displays. LCD operation is supported during Deep Sleep
refreshing a small display buffer (4 bits; 1 32-bit register per port).
Document Number: 002-00123 Rev. *I
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