content_image/969281.jpg
## 2.2.4 CPC drawer power 

Each CPC drawer gets its power from two DCAs. The DCAs provide the required power for the drawer in an  n +1 configuration. Loss of one DCA leaves enough power to meet power requirements for the entire drawer. The DCAs can be concurrently serviced and are accessed from the rear of the frame A. 

## 2.3 Single chip modules 

Figure 2-12 shows the location of DCAs on the backplane of the A frame. 

<img src='content_image/969281.jpg'>

The single chip module (SCM) is a multi-layer metal substrate module that holds one PU chip or an SC chip. Both CP and SC chip size is 696 mm$^{2}$ (25.3 mm x 27.5 mm). Each CPC drawer has six (model M01-M04) or seven SCMs (model M05), five or six PU SCMs (6.1 billion transistors each), and one SC SCM (9.7 billion transistors). 

