1. Programmable System-on-Chip (PSoC) General Overview Embedded Architectures EE446

2. Typical Microcontroller Purposes
The purpose for uC’s is to interface multiple types of hardware.
Digital Input/Outputs:
Switches
Relays
LEDs
Digital Communications: I2C, SPI
Analog Input/Outputs
Computer uC
Thermal
Gyro
Acceleration

3. Example of Hardware Interfacing

4. Regular Microcontroller Caveats
What if you need more Analog Inputs?
What if you need more Interrupts?
Advanced projects: more PWMs needed?
Use external circuitry
Buy a larger microcontroller

5. What is a Programmable System-on-Chip (PSoC)?
A customizable microcontroller that includes flexible analog and digital logic blocks.
Analog blocks:
High-resolution inputs (up to 20-bit)
4 Digital-to-Analog Converters
Digital logic blocks (UDBs):
A wide mix of digital peripherals can be implemented into a single chip.
Up to 4 voltage domains
Almost all pins can be flexible in terms of being digital or analog.

6. What is a Programmable System-on-Chip (PSoC)?
(Powered by ARM Core)
Provides above features plus ARM processor benefits:
Up to 67Mhz
Flash: Up to 256kb
SRAM: Up to 65kb
Up to 70 I/O pins

7. General Overview of PSoC Features

9. Cypress PSoC IDE
API

10. Cypress PSoC IDE (Block Configuration)
Read up some of these options

11. PSoC Pin Routing

12. PSoC Main Program Code
ISR Flag
Main loop
ISR Flag

13. API’s for the PSoC Blocks

14. API’s for the PSoC Blocks

15. Universal Digital Blocks
A UDB is a combination of uncommitted logic (PLDs), structured logic (datapath), and a flexible routing scheme.
The largest PSoC contains up to 24 general-purpose digital logic subsystems (UDBs)
PLD:
Implements state machines and simple combinational logic.
Datapath:
Dynamically configurable ALU
Contains Input/Output FIFOs
Connects to the CPU/DMA and other UDB’s

16. Top-level UDB Block Diagram

17. Top-level UDB Routing Diagram

18. Extensive Uses of UDBs
Examples of possible hardware configurations on a single (and largest) PSoC chip:
12 UARTs or
28 PWMs
For a normal microcontroller, this configuration is impossible without resorting to additional external hardware, such as:
Daisy-chain or bus-connected peripherals:
Microcontrollers
I2C/SPI-connected hardware for UART, PWM, etc.

19. Extensive Uses of UDBs Technology Mapping Summary

20. Extensive Uses of UDBs Technology Mapping Summary

21. PSoC Top-Level Analog Routing Diagram

22. PSoC Analog Routing Analog Local Bus Analog Global Bus Analog Mux Bus
4 on left side, 4 on right side
Connects to analog resource blocks only
No access to GPIO’s
Analog Global Bus
Connects I/O to analog resource blocks on same side
Connects to GPIO on their respective quadrant
8 routes on left side, 8 routes on right side
Analog Mux Bus
Connects the buses to the ‘outside’ world
Can connect to all GPIO’s and all analog resource blocks

23. PSoC Die Quadrants Analog Routing
Global Bus
The
analog global bus has eight routes on each side, AGL[7:0]
on the left, and AGR[7:0] on the right. Within each side, the
bus is divided into two groups, AGR[3:0] and AGR[7:4] for
the right side, and AGL[3:0] and AGL[7:4] for the left side.
The lower four globals on each side are routed to the GPIO
on the lower half of the die and the upper four globals on
each side are routed to the GPIO on the upper half of the
die. All eight analog globals on each side get routed to
ARBs on the same side

24. Detailed Analog Routing

25. Interrupts

26. Why have interrupts? An external event that needs immediate attention.
An ‘emergency’ switch
A long-running timer
PSoC-5 supports 16 system interrupts and 32 from peripherals.
Tail Chaining (Back-to-Back)
Late Arrival (Lower  Higher)
Reprioritize Interrupts
Same Priority?
Fixed Function  DMA  UDB

27. Interrupts
“Have any of you taken EE445?”
Reason why you need interrupts for the hardware
Some modules that are used needs immediate attention in real time.

28. Interrupt Usage Sonar UART: Servo Hardware: Motor Encoders:
Send a command every 20msec.
Motor Encoders:

29. Interrupt Vector Table

30. How Interrupts Work

31. Interrupt Setup and ISR

32. Tail Chaining Interrupts

33. Late Arrival Interrupts

34. Polling vs Interrupting
Signals can happen too fast for the CPU to read or process!

35. Example PSoC Project Firmware Overview
I/O Communications
Inputs
From
Sensors
Outputs To
Devices

36. Raw Sensor Data Collection to the Host PC
Digital:
I2C used in Gyroscopes, Accelerometers, Magnetometers (IMU), and Temperature Sensor
UART from 9600bps (8N1)
For this particular usage, very inefficient.
Requires interrupts and additional code complexity.
Very slow data updates.
ADC Settings and Inputs:
70,000 Samples Per Second (currently)
Vcc = 5 Volt (Reference)
Raw value range:
0v  5v
0 

37. PSoC Data Output
Raw ADC Values: 85 updates/sec over Serial bps (8N1)
Servo
Position
Infrared
Gyro
X-Axis
Gyro
Y-Axis
Gyro
Z-Axis
Sonar
(analog)

38. Host PC Application GUI