sx1511b Semtech Corporation, sx1511b Datasheet - Page 15

• Manufacturer Part Number: sx1511b
• Description: World??s Lowest Voltage Level Shifting Gpio With Driver Keypad Engine
• Manufacturer: Semtech Corporation

ADVANCED COMMUNICATIONS & SENSING
Please note that a brown-out event is defined as a transient event on VDDM. If VDDM is attached to a battery,
then the gradual decay of the battery voltage will not be interpreted as a brown-out event.
Please also note that a sharp rise in VDDM (> 1V/us) may induce a circuit reset.
4.4.2
Writing consecutively 0x12 and 0x34 to RegReset register will reset all registers to their default values.
4.5
The SX1510B, SX1511B and SX1512B SPI interface operates only in slave mode. 4 lines are used to exchange
data between an external master host and the slave device:
The SX1510B, SX1511B and SX1512B have a few user-accessible internal 8-bits registers to set the various
parameters of operation (Cf. §5 for detailed configuration registers description). The SPI interface has been
designed for program flexibility, in that any register can be written or read independently of each other.
4.5.1
Successive register data can be written by the master without repeating the address byte, the register address
can be automatically incremented or kept fixed depending on the setting programmed in RegMisc.
4.5.2
Successive register data can be read by the master without repeating the address byte, the register address will
be automatically incremented or kept fixed depending on the setting programmed in RegMisc.
Rev 3 – 9
To read a value from a configuration register the timing diagram below should be carefully followed by the uC.
To write a value into a configuration register the timing diagram below should be carefully followed by the uC.
4. During a brown-out event, if VDDM drops above VDROPH a reset will not occur.
5. During a brown-out event, if VDDM drops between VDROPH and VDROPL a reset may occur.
6. During a brown-out event, if VDDM drops below VDROPL a reset will occur next time VPOR is crossed.
SPI Interface
Software (RegReset)
NSS : Slave select input (active low)
SCK : Clock input
SI : Data input
SO : Data output
WRITE
READ
th
Sept. 2010
SO
SO
NSS
SCK
SI
NSS
SCK
SI
Figure 10 – SPI Read Operation
Figure 9 - SPI Write Operation
15
World’s Lowest Voltage Level Shifting GPIO
SX1510B/SX1511B/SX1512B
with LED Driver and Keypad Engine
www.semtech.com