I have a problem programming your LMX2492 pll synthezier.
When power is applied to device it consumes 3mA. I assume that it is in powerdown mode according to datasheet
First question is: will the consuption change when i will write powerup sequence to device? What is the simplest command to see that i succesfully programmed device?
You have and error in datasheet in serial data input timing section. According to it first i have to write "read/write" bit and than 24bit register - i assume that it is an error. So 24th bit is read/write bit, than 15 address bits, and 8 bit of data. So for writing power up command i need to write 0x0, 0x2, 0x1?
I use simple program for interfacing with device:
ldi r22,0x0
ldi r23,0x2
ldi r24,0x1
ldi r30,0x16
ldi r18,0x03
rcall spi_write
;Write bytes via SPI
;r30- pointer to start data byte(Z-Pointer)
;r18- number of bytes
;r19- bit counter
;LE-PB2 F1/F2-PB1 Alarm-PB0 CLK-PB4 DATA-PB3 LOCK-PB3(resistor)
spi_write:
; send write operation
sbi PORTB,0x2
ldi r21,0x2
rcall delay
cbi PORTB,0x4
ldi r21,0x2
rcall delay
cbi PORTB,0x2
ldi r21,0x2
rcall delay
next_byte:
ldd r16,Z+0
ldi r19,0x8
next_bit:
sbi PORTB,0x3
sbrs r16,0x07
cbi PORTB,0x3
ldi r21,0x2
rcall delay
sbi PORTB,0x4
ldi r21,0x2
rcall delay
cbi PORTB,0x4
lsl r16
dec r19
brne next_bit
ldi r21,0x2
rcall delay
inc r30
dec r18
brne next_byte
cbi PORTB,0x4
sbi PORTB,0x2
ret
This program worked well with Analog Devices syntheziers, wich have the same interface(if beliave to your datasheet).