You can able to configure ASA in multiple context mode with CSM ver 3. When a firewall device uses a single security context, it appears to the network and to CSM as a single firewall device, just as a firewall with no support for contexts. However, when you configure a firewall device to use multiple security contexts, each security context appears, from the network perspective, as a standalone firewall device. As such, representing multiple firewalls that reside within the same physical appliance requires special care.
In multi context configuration, the appliance acts as multiple firewalls. For each security context, a unique firewall inspects and filters traffic traversing among the networks attached to the interfaces of that security context. Each context is "unaware" of other contexts defined on the same security appliance.
http://www.cisco.com/en/US/docs/security/security_management/cisco_security_manager/security_manager/3.1/user/guide/pxchap.html#wp1167617