Nera Inmarsat-c, Service Manual, Page: 46 / 228

2.3 Terminal unit, IC-215
2-26
4) Back up
I/O interface of U7 (FDC37C935APMQFP), which has RTC function and the function of the
interface of the printer and FDD, and S-RAM of U3 and U4 (K6T1008C2E) are backed up
by Lithium battery. The RTC data is used as a time stamp;
- [F1]-3: Save
- [F6]: Log
2.3.3 Memory contents
Table 2.3.8 lists the volume and the memorized contents of each memory.
Table 2.3.8 Memory volume
Board Parts number Model Volume Remarks
U22: S-RAM CY62146VLL 256 kbyte Backup (C90)*
U15: EEROM CAT25C64P 64 kbits Serial EEPROM
256 kbyte Built-in ROM
RF CON
/CPU
(16P208)
U14: CPU HD64F7065A
8 kbyte Built-in RAM
U3and U4: S-RAM K6T1008C2E (128 Kx8)x2 Backup (BATT-1)**
U14: Flash ROM MBM29F800BA 8 M bits
U22 and U23: D-RAM MSM5118165D F 1 M (word)×16 (bit)x2
U13: D-RAM MSM5118165D F 1 M (word)×16 (bit)
TERM
CPU
(16P0209)
U28: CPU HD6417615 AF 8 k bytes Built-in RAM
Note)
*: S-RAM, U22 on RF CON/CPU board is
b
acked up by the charge of the capacitor, C90
(2.2F) for 72 hours as well as optional GPS board, GN-79.
**: S-RAM, U3 and U4 on TERM CPU board is
b
acked up by the lithium battery
(BATT-1: CR2450 F2ST2L) for more than 2 years. The battery life is about 5 years.