Designing SOCs with Configured Cores

8.6. Direct Input and Output Ports

Two of the Diamond 212GP controller core’s unique features are its 32-bit direct input and output ports, which are the same I/O ports found on the Diamond 108Mini processor core. The input and output wires on these ports connect directly to special software-visible registers in the processor core and can be used for general-purpose signaling, interrupt generation, serial communications, pulse-width modulation, and other sorts of status and control functions on the SOC. Special instructions read and manipulate the contents of these port registers. Table 8.5 lists these port instructions.

Table 8.5. Special input- and output-port register instructions

Instruction	Definition
CLRB_EXPSTATE	Clear any bit in the output-port ...