Toshiba satellite a20 series Benutzerhandbuch

1.2 System Unit Block Diagram 

 

 KBC/EC (Keyboard Controller/Embedded Controller) 

•  One M306K9FCLRP chip functions as both KBC and EC. 

•  KBC has the following functions: 

–   Scan controller to check status of keyboard matrix 
–   Interface controller between the keyboard scan controller and the system 

•  EC has the following functions: 

–   Power supply sequence control 
–   System I/F 
–   Thermal conditions control 
–   Flash rewriting 

 

 PSC (Power Supply Controller) 

•  One TMP87PM48V chip is used. 
•  This controller controls the power sources. 

 Onboard memory: 0MB 

 Optional memory 

Two SO-DIMM slots are available for 128, 256, 512MB and 1GB memory modules, 
consisting of SDRAM chips.  

•  PC2100 

•  3.3 volts operation 

•  No parity bit 
•  Data transfer width is 64-bit 

•  128/256/512/1024 MB selectable 

– 128MB:  eight 128Mbit (8M x 16bit) chips 
– 128MB:  four 256Mbit (16M x 16bit) chips 
– 256MB:  eight 256Mbit (16M x 16bit) chips 

– 512MB:  eight 512Mbit (32M x 16bit) chips 
– 1GB: eight 1Gbit (64M x 16bit) chips 

 

 Sound CODEC 

•  One AD1981B chip is used. 
•  Internal Audio Controller is integrated into the MM1535+ chip. 
Both chips are used as the CODEC chip. 

 Battery E

2

 PROM: ST24C04FM 

•  One ST24C04FM equivalent (128 words × 16-bit, I

2

C-Interface) is used. 

This memory maintains records of battery use.