EE-PROM MEMORY IN SYNTHESIZER/PLL TO STORE DEVIATION INFORMATION
Original Publication Date: 1989-Aug-01
Included in the Prior Art Database: 2001-Nov-08
Publishing Venue
Motorola
Related People
Abstract
In our present SABER radio the modulation deviation of the synthesizer is set through two digital attenuators. The method in which these attenuators are programmed is very inefficient. Each channel in the radio has adigital word associated with that frequency setting. The deviation must be measured and tuned for each channel then programmed into the EE-Prom. This is a tremendously time consuming process. We do have some improvement in our factory by having certain deviation forecast algorithms but these still require that several deviation measurements be made on each radio. This data is saved with the particular radio and synthesizer and then used to calculate the attentuator settings for any given channel. These algorithms do not help in the field where there are no BIG-FOOT autotest systems. This process must be performed on every radio or every time a syn- thesizer is replaced.
MOlYlROLA Technical Developments Volume 9 August 1989
EE-PROM MEMORY IN SYNTHESIZEWPLL TO STORE DEVIATION INFORMATION
by Steve Einbinder
In our present SABER radio the modulation deviation of the synthesizer is set through two digital attenuators. The method in which these attenuators are programmed is very inefficient. Each channel in the radio has adigital word associated with that frequency setting. The deviation must be measured and tuned for each channel then programmed into the EE-Prom. This is a tremendously time consuming process. We do have some improvement in our factory by having certain deviation forecast algorithms but these still require that several deviation measurements be made on each radio. This data is saved with the particular radio and synthesizer and then used to calculate the attentuator settings for any given channel. These algorithms do not help in the field where there are no BIG-FOOT autotest systems. This process must be performed on every radio or every time a syn- thesizer is replaced.
An improved approach is to some how save the deviation data in the synthesizer. This deviation datacould be saved in a memory location within the module at synthesizer final test since it is measured at this point anyway. Now when a synthesizer is placed in the radio, the microprocessor can read the information and com- pute the attenuator settings. The result can be programmed into the attenuator. The radio has essentially tuned itself up. Thus an en...