| Line 23... |
Line 23... |
- simple Forth-like assembly language (43 instructions)
|
- simple Forth-like assembly language (43 instructions)
|
- single cycle instruction execution
|
- single cycle instruction execution
|
- automatic generation of I/O ports
|
- automatic generation of I/O ports
|
- configurable instruction, data stack, return stack, and memory utilization
|
- configurable instruction, data stack, return stack, and memory utilization
|
- extensible set of peripherals (I2C busses, UARTs, AXI4-Lite busses, etc.)
|
- extensible set of peripherals (I2C busses, UARTs, AXI4-Lite busses, etc.)
|
|
- optional interrupt peripheral and interrupt handler
|
- extensible set of macros
|
- extensible set of macros
|
- memory initialization file to facilitate code development without rebuilds
|
- memory initialization file to facilitate code development without rebuilds
|
- simulation diagnostics to facilitate identifying code errors
|
- simulation diagnostics to facilitate identifying code errors
|
- conditionally included I/Os and peripherals, functions, and assembly code
|
- conditionally included I/Os and peripherals, functions, and assembly code
|
|
|
| Line 678... |
Line 679... |
|
|
User defined peripherals can be in the same directory as the architecture file
|
User defined peripherals can be in the same directory as the architecture file
|
or a subdirectory named "peripherals".
|
or a subdirectory named "peripherals".
|
|
|
|
|
|
INTERRUPTS
|
|
================================================================================
|
|
|
|
Interrupts are enabled by including an interrupt peripheral in the architecture
|
|
file and an interrupt handler in the assembly code.
|
|
|
|
Incorporating an interrupt adds the following output ports as strobes:
|
|
|
|
O_INTERRUPT_DIS disable interrupts
|
|
O_INTERRUPT_ENA enable interrupts
|
|
|
|
and the following 3 macros
|
|
|
|
.dis disable interrupts
|
|
Note: This is equivalent to .outstrobe(O_INTERRUPT_DIS)
|
|
.ena enable interrupts
|
|
Note: This is equivalent to .outstrobe(O_INTERRUPT_ENA)
|
|
.returni return from interrupt handler and enable interrupts
|
|
Note: This is equivalent to the 3 instruction sequence
|
|
"O_INTERRUPT_ENA return outport"
|
|
Note: The assembler prohibits the ".return" macro in the
|
|
interrupt handler and the ".returni" macro anywhere other
|
|
than the interrupt handler.
|
|
|
|
See examples/interrupt for a demonstration of an interrupt handler for two
|
|
events, one external to the processor and one internal to the processor.
|
|
|
|
The interrupt handler included in core/9x8/peripherals handles one to eight
|
|
interrupt sources. See core/9x8/doc/interrupt.html for instructions on creating
|
|
custom interrupt peripherals, possibly with more interrupt sources.
|
|
|
|
|
PARAMETER and LOCALPARAM
|
PARAMETER and LOCALPARAM
|
================================================================================
|
================================================================================
|
|
|
Parameters are incorporated through the PARAMETER and LOCALPARAM configuration
|
Parameters are incorporated through the PARAMETER and LOCALPARAM configuration
|
commands. For example, the clock frequency in hertz is needed for UARTs for
|
commands. For example, the clock frequency in hertz is needed for UARTs for
|
