M08035 Datasheet, PDF (31/49 Pages) M/A-COM Technology Solutions, Inc. – SD, HD, 3G Multi-rate Reclocker

Functional Description
4.6.4
MIC Mode Operation
In this mode, the reclocker is initialized with an EEPROM. To use this mode, the EEPROM must be programmed
with the register data required. The I²C address of the memory can be 50h, 51h, 52h or 53h; the reclocker loads its
register contents from this address.
This mode is enabled when the I²C mode is set and address 20h has been hardwired on the address pins. When
the reclocker locates the memory at one of the above addresses, it sets itself into I²C quasi-master mode. It will
then load its registers from the EEPROM. Addresses 00h to 19h should be used when only one reclocker is used.
Register 0Fh contains the number of slave reclockers; if there are none this is set to 0.
Once the master has finished the task of downloading the registers, it will revert to slave mode at address 20h and
can be accessed for debugging purposes.
Note that when using MIC power mode supply, ramp time is important. The EEPROM should be powered from the
same supply as DV_DDIO and the ramp up of the supply should be < 100 ms. If the ramp time is not met, the
reclocker I²C will time-out before the EEPROM is ready to receive serial data.
The target EEPROM is the AT24C01 or equivalent.
If there is more than one reclocker to be programmed, a checksum is used to confirm that the data is correct. This
works as follows:
1. The slave reclocker sums all registers from 00h to 1Ah, then truncates this to leave the 8 LSB bits. This is then
compared with the value 2Eh. If it is not equal, then the registers are not loaded and it returns to the default
value. It will then try up to 512 times before timing out. When the checksum is equal to 2Eh, the registers are
loaded with the EEPROM settings.
2. To make the checksum = 2Eh, register 1Ah must be programmed with the 8 LSBs from the following
calculation:
Register 1Ah = 2Eh - (sum of registers 00h to 19h)
M08035, M08045 Data Sheet V1
MACOM™
31
080x5-DSH-001