"""
The LOAD operation.
Loads a value from data memory into a module.
"""
from itertools import product
from ..language_defs import (
INSTRUCTION_GROUPS,
SRC_REGISTERS,
DEST_REGISTERS,
MODULE_CONTROL,
FLAGS,
instruction_byte_from_bitdefs,
)
from ..operation_utils import assemble_instruction, match_and_parse_line
from ..data_structures import (
get_arg_def_template, get_machine_code_byte_template
)
_NAME = "LOAD"
[docs]def generate_microcode_templates():
"""
Generate microcode for all the LOAD instructions.
Returns:
list(DataTemplate): DataTemplates for all the LOAD instructions.
"""
data_templates = []
signatures = generate_signatures()
for signature in signatures:
templates = generate_operation_templates(signature)
data_templates.extend(templates)
return data_templates
[docs]def generate_signatures():
"""
Generate the definitions of all possible arguments passable.
Returns:
list(list(dict)): All possible arguments. See
:func:`~.get_arg_def_template` for more information.
"""
signatures = []
sources = ("ACC", "A", "B", "C", "PC", "SP")
destinations = ("ACC", "A", "B", "C")
for src, dest in product(sources, destinations):
signature = []
arg0_def = get_arg_def_template()
arg0_def["value_type"] = "module_name"
arg0_def["is_memory_location"] = True
arg0_def["value"] = src
signature.append(arg0_def)
arg1_def = get_arg_def_template()
arg1_def["value_type"] = "module_name"
arg1_def["value"] = dest
signature.append(arg1_def)
signatures.append(signature)
for dest in destinations:
signature = []
arg0_def = get_arg_def_template()
arg0_def["value_type"] = "constant"
arg0_def["is_memory_location"] = True
signature.append(arg0_def)
arg1_def = get_arg_def_template()
arg1_def["value_type"] = "module_name"
arg1_def["value"] = dest
signature.append(arg1_def)
signatures.append(signature)
return signatures
[docs]def generate_operation_templates(signature):
"""
Create the DataTemplates to define a load with the given args.
Args:
signature (list(dict)): List of argument definitions that
specify which particular load operation to generate
templates for.
Returns:
list(DataTemplate) : Datatemplates that define this load.
"""
instruction_byte_bitdefs = generate_instruction_byte_bitdefs(signature)
flags_bitdefs = [FLAGS["ANY"]]
control_steps = generate_control_steps(signature)
return assemble_instruction(
instruction_byte_bitdefs, flags_bitdefs, control_steps
)
[docs]def generate_instruction_byte_bitdefs(signature):
"""
Generate bitdefs to specify the instruction byte for these args.
Args:
signature (list(dict)): List of argument definitions that
specify which particular LOAD operation to generate
the instruction byte bitdefs for.
Returns:
list(str): Bitdefs that make up the instruction_byte
"""
if signature[0]["value_type"] == "constant":
instruction_byte_bitdefs = [
INSTRUCTION_GROUPS["LOAD"],
SRC_REGISTERS["CONST"],
DEST_REGISTERS[signature[1]["value"]],
]
elif signature[0]["value_type"] == "module_name":
instruction_byte_bitdefs = [
INSTRUCTION_GROUPS["LOAD"],
SRC_REGISTERS[signature[0]["value"]],
DEST_REGISTERS[signature[1]["value"]],
]
return instruction_byte_bitdefs
[docs]def generate_control_steps(signature):
"""
Generate control steps for these args.
Args:
signature (list(dict)): List of argument definitions that
specify which particular load operation to generate the
control steps for.
Returns:
list(list(str)): List of list of bitdefs that specify the
control steps.
"""
if signature[0]["value_type"] == "module_name":
# E.g. LOAD [A] B
control_steps = [
[
MODULE_CONTROL[signature[0]["value"]]["OUT"],
MODULE_CONTROL["MAR"]["IN"],
],
[
MODULE_CONTROL["RAM"]["SEL_DATA_MEM"],
MODULE_CONTROL["RAM"]["OUT"],
MODULE_CONTROL[signature[1]["value"]]["IN"],
],
]
elif signature[0]["value_type"] == "constant":
# E.g. LOAD [$var] ACC
control_steps = [
[
MODULE_CONTROL["PC"]["OUT"],
MODULE_CONTROL["MAR"]["IN"],
],
[
MODULE_CONTROL["RAM"]["SEL_PROG_MEM"],
MODULE_CONTROL["RAM"]["OUT"],
MODULE_CONTROL["MAR"]["IN"],
MODULE_CONTROL["PC"]["COUNT"],
],
[
MODULE_CONTROL["RAM"]["SEL_DATA_MEM"],
MODULE_CONTROL["RAM"]["OUT"],
MODULE_CONTROL[signature[1]["value"]]["IN"],
],
]
return control_steps
[docs]def parse_line(line):
"""
Parse a line of assembly code to create machine code byte templates.
If a line is not identifiably a LOAD assembly line, return an empty
list instead.
Args:
line (str): Assembly line to be parsed.
Returns:
list(dict): List of machine code byte template dictionaries or
an empty list.
"""
match, signature = match_and_parse_line(
line, _NAME, generate_signatures()
)
if not match:
return []
instruction_byte = instruction_byte_from_bitdefs(
generate_instruction_byte_bitdefs(signature)
)
mc_bytes = []
mc_byte = get_machine_code_byte_template()
mc_byte["byte_type"] = "instruction"
mc_byte["bitstring"] = instruction_byte
mc_bytes.append(mc_byte)
if signature[0]["value_type"] == "constant":
mc_byte = get_machine_code_byte_template()
mc_byte["byte_type"] = "constant"
mc_byte["constant"] = signature[0]["value"]
mc_bytes.append(mc_byte)
return mc_bytes