Specifications

46 Software Interface
3.4 Initialization
The host must initialize the module before using it. Initialization occurs
in three stages.
1. The host initializes the module’s data transport system.
2. The host loads the module microcode into the module’s private
memory, then starts executing the microcode.
3. The microcode synchronizes with the telephone line interface
hardware, then reads back that hardware’s identification code.
3.4.1 Stage 1
Initialization of the module’s data transport system executes as follows:
1. The module is reset. The reset can occur either from the host
initiating a Q-bus or a CSR reset, or from a module power-up.
2. After the reset, the module automatically begins to execute
initialization microcode. First, the module performs a series of
self-tests to verify that all its major circuits are in working order.
If the module fails these tests, it informs the host by entering an
appropriate error message in the module state field of the CSR (Table
3-2). If the module state field contains an error message, the first
longword in shared memory contains further information about the
message.
3. If the module passes the self-tests, it enters a ready message in the
module state field of the CSR. Also, the green LED on the back of the
module goes on and the module sets the host alert bit in the CSR. The
module waits for the host to ackowledge the host alert.
4. The host acknowledges the host alert by clearing the host alert bit in
the CSR. Then the host checks the module state field in the CSR to
make sure the module passed the self-tests.
If the module is ready, the host enables the module shared memory
by setting the memory enable bit and entering a bank selection value
into the memory bank field in the CSR. The host also initializes the
rings in shared memory.
5. The host requests a module alert by setting the module alert bit in
the CSR.