SLIDE 1
MSP430F1611
Ports: P1-P6 Each port == 8 pins
Hardware MSP430F1611 Ports: P1-P6 Each port == 8 pins Memory, - - PowerPoint PPT Presentation
Hardware MSP430F1611 Ports: P1-P6 Each port == 8 pins Memory, - - PowerPoint PPT Presentation
Hardware MSP430F1611 Ports: P1-P6 Each port == 8 pins Memory, clock RAM: between 256 and 16K bytes, depending on the model Code (flash == EEPROM): from 8KB to 256KB Max clock rate up to 25MHz Memory layout Port access These ones can
SLIDE 2
SLIDE 3
Memory, clock
RAM: between 256 and 16K bytes, depending on the model Code (flash == EEPROM): from 8KB to 256KB Max clock rate up to 25MHz
SLIDE 4
Memory layout
SLIDE 5
Port access
These ones can trigger interrupts
SLIDE 6
Sensor interfaces
2 UARTs, each reconfigurable into: SPI I2C direct pin access ADC (8 ports usable for this purpose) DAC (2 ports) – for actuators
SLIDE 7
UART
Two ways (separate wires) Tx/Rx Digital signal (two levels) assuming:
limited length of a data unit (byte) both parties know the fixed duration of a bit
low high start stop 1 1 1 1 1
SLIDE 8
SPI
The primary difference:
clock is provided on a separate wire it works both ways at once (sort of)
IN OUT CLK
SLIDE 9
SPI timing
SLIDE 10
SPI implementation
b7 b0 b7 b0 Master Slave SOMI SIMO CLK
There are two byte-sized shift registers interconnected by the two data lines. A transfer always involves exchanging their contents (so it is always both ways).
SLIDE 11
I2C
Serial DAta Serial CLock
SLIDE 12
Example: SHT7x
SLIDE 13
Connection
SLIDE 14
Protocol
SLIDE 15
Even simpler
Temperature sensor Single-wire interface, i.e., no clock!
SLIDE 16
Connecting
SLIDE 17
Communication (startup)
SLIDE 18
Communication (read/write)
SLIDE 19
Device identification protocol
Command “search ROM” 0xF0 All devices respond with subsequent bits of their IDs (64 of them), each bit being reported twice positive + negated. The micro responds after every bit with 0 or 1 selecting the subset of devices that it wants to continue with. The remaining
- nes remain silent until the next reset pulse.
00 – there are devices with both 0 and 1 on this position 01 – all devices have 0 on this position 10 – all devices have 1 on this position
SLIDE 20
ADC (MSP430)
Up to 8 configurable pins (independent inputs) 12-bit accuracy: d = 4096 x (V - Vref-) / (Vref+ - Vref-)
measured lower bound upper bound reference
Can be sampled automatically at prescribed rate
SLIDE 21
Example PAR
Vref+ = 1.2V (Zener) Vref- = 0
c = f x d f = 1200x5/4096 f = 1.465