AK1542A Datasheet, PDF (19/37 Pages) Asahi Kasei Microsystems – 20 to 600MHz Integer-N Frequency Synthesizer

[AK1542A]
Notes for writing into registers
(1) The data at addresses 0x02 and 0x03 are committed to all related circuits when address 0x01 is written, which means
that the data of these 3 addresses (0x01, 0x02 and 0x03) are committed to all related circuits at the same time.
(2) Addresses 0x04 and 0x05 could be written individually from other addresses.
(3) The initial register values are not defined. Therefore, even after [PDN1] is turned ON, each bit value remains undefined.
In order to set all register values, it is required to write the data in all addresses of the register.
○ Examples of writing into registers
(Ex. 1) Power-On ⇒Writing these three-word data is required.
(1) Write a charge pump current value to address 0x02.
The data at address 0x02 is not committed to all related circuits at this time. Instead, it is stored in the on-chip buffer.
(2) Write a division number for the prescaler and a reference counter value to address 0x03.
The data at the address 0x03 is not committed to all related circuits at this time. Instead, it is stored in the on-chip buffer.
(3) Write values for A counter and B counter at the address 0x01.
The data of these 3 addresses (0x01, 0x02 and 0x03) are committed to all related circuits at this time.
(Ex. 2) Changing frequency settings
(1) Write values for A counter and B counter at the address 0x01.
The data of these 3 addresses (0x01, 0x02 and 0x03) are committed to all related circuits at a time. The last data written
into addresses 0x02 and 0x03 are committed.
(Ex. 3) Changing charge pump current ⇒Writing these two-word data is required.
(1) Write a charge pump current value at the address 0x02.
The data in address 0x02 is not committed to all related circuits at this time. Instead, it is stored in the on-chip buffer.
(2) Write values for A counter and B counter at the address 0x01.
The data of these 3 addresses (0x01, 0x02 and 0x03) are committed to all related circuits at a time. The last data written
into address 0x03 is committed.
(Ex. 4) Changing reference dividing number ⇒Writing these two-word data is required.
(1) Write a division number for the prescaler and a reference counter value at the address 0x03.
The data at the address 0x03 is not committed to all related circuits at this time. Instead, it is stored in the on-chip buffer.
(2) Write values for A counter and B counter at the address 0x01.
The data of these 3 addresses (0x01, 0x02 and 0x03) are committed to all related circuits at a time. The last data written
into address 0x03 is committed.
MS1399-E-00
- 19 -
2012/3