Specifications

3
Software Interface
This chapter describes the software interface that the DECvoice hardware
uses with the host system. Specifically, this chapter describes:
• communication between DECvoice and the host
• data movement between DECvoice and the host
• initialization of the DECvoice DTC04 module
• DECvoice read-only memory commands
3.1 Q-bus Interface
The Q-bus interface controls communication between the DECvoice
DTC04 module and the host system. The Q-bus interface consists of the
control and status register (CSR) and a Q-bus memory window. The CSR
lets the host control data movement to and from the DTC04 module,
and checks the operation status of the module. The memory window
provides communication space between the host and module. This section
describes the CSR in detail.
3.1.1 Control and Status Register
The CSR is a read-write register with a width of one 16-bit word. The
host uses the CSR to reset the module, to determine the module’s status,
and to manage the alert interrupts that flow between the module and the
host.
You can set the address of the CSR to any location in I/O memory space
by setting switches on the module. Chapter 1 describes this procedure in
detail.
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