An apparatus, comprising: a glucose sensor (101, 110) including a working electrode having a portion in fluid contact with interstitial fluid under a skin surface; a memory unit (560, 570) having a first plurality of memory locations configured to store a first predetermined type of data and a second plurality of memory locations configured to store a second predetermined type of data; and a processing unit (160, 510) operatively coupled to the glucose sensor (101, 110) and the memory unit (560, 570), the processing unit (160, 510) configured to process analyte related signals generated by the glucose sensor (101, 110), and to control data storage in and retrieval from the memory unit (560, 570); wherein, the first predetermined type of data includes error data, the second predetermined type of data includes monitored physiological condition data, wherein when an error condition associated with operation of the glucose sensor (101, 110) is detected by the processing unit (160, 510), the processing unit is configured to store data associated with the first predetermined type of data in a subset of the second plurality of memory locations of the memory unit (560, 570); and further wherein, the processing unit (160, 510) is configured to store an error condition indicator in a subset of the first plurality of memory locations of the memory unit (560, 570), and characterised in that, when the error condition is detected by the processing unit (160, 510), a first portion of a plurality of error data bits corresponding to the detected error condition is stored in the subset of the first plurality of memory locations, and a second portion of the plurality of error data bits is stored in the subset of the second plurality of memory locations, the first portion and the second portion comprising the entire error data bits. a glucose sensor (101, 110) including a working electrode having a portion in fluid contact with interstitial fluid under a skin surface; a memory unit (560, 570) having a first plurality of memory locations configured to store a first predetermined type of data and a second plurality of memory locations configured to store a second predetermined type of data; and a processing unit (160, 510) operatively coupled to the glucose sensor (101, 110) and the memory unit (560, 570), the processing unit (160, 510) configured to process analyte related signals generated by the glucose sensor (101, 110), and to control data storage in and retrieval from the memory unit (560, 570); wherein, the first predetermined type of data includes error data, the second predetermined type of data includes monitored physiological condition data, wherein when an error condition associated with operation of the glucose sensor (101, 110) is detected by the processing unit (160, 510), the processing unit is configured to store data associated with the first predetermined type of data in a subset of the second plurality of memory locations of the memory unit (560, 570); and further wherein, the processing unit (160, 510) is configured to store an error condition indicator in a subset of the first plurality of memory locations of the memory unit (560, 570), and characterised in that, when the error condition is detected by the processing unit (160, 510), a first portion of a plurality of error data bits corresponding to the detected error condition is stored in the subset of the first plurality of memory locations, and a second portion of the plurality of error data bits is stored in the subset of the second plurality of memory locations, the first portion and the second portion comprising the entire error data bits. wherein, the first predetermined type of data includes error data, the second predetermined type of data includes monitored physiological condition data, wherein when an error condition associated with operation of the glucose sensor (101, 110) is detected by the processing unit (160, 510), the processing unit is configured to store data associated with the first predetermined type of data in a subset of the second plurality of memory locations of the memory unit (560, 570); and further wherein, the processing unit (160, 510) is configured to store an error condition indicator in a subset of the first plurality of memory locations of the memory unit (560, 570), and characterised in that, when the error condition is detected by the processing unit (160, 510), a first portion of a plurality of error data bits corresponding to the detected error condition is stored in the subset of the first plurality of memory locations, and a second portion of the plurality of error data bits is stored in the subset of the second plurality of memory locations, the first portion and the second portion comprising the entire error data bits.