You were right, with small changes temperature sensor is working correctly (CPOL = 0 | CPHA = 0) but... ;) rtc chip is not. When data wires are connected i`m reading random values almost always 0x00.

Another issue is that i must 'twist' vcc/gnd cable
to rtc chip to read proper data i dont know why. Cable is about 10cm long. Strange for me.

I will try to put rtc in to the 3wire mode (not spi) like temp sensor and post results tomorow.

one other question
this diagrams in 8252 datasheet are not enough clear for me.
when
CPHA = 0
master write at rising edge
master read at falling edge

CPHA = 1
master write at falling edge
master read at rising edge

CPOL only set clock level when idle
is that true ?

and another one: i readed that the clock polarity for ds1306 is not important (CPOL=0 or CPOL=1) becos chip is sampling clock before transmision and detecting proper idle level. is that true ?

Lucas Bajger