N4VM Namespace Reference

Functions
void	_nest (IU xt)
void	_init ()
void	_dump (IU p0, U16 sz0)
void	_immediate (U16 op)
void	_clock ()
void	_dplus ()
void	_dminus ()
void	_dneg ()
IU	_invoke (U8 op, IU xt=0)
void	setup (const char *code, Stream &io, U8 ucase)
void	push (int v)
int	pop ()
void	serv_isr ()
	interrupt service routine
void	outer ()
	outer-interpreter

Detailed Description

nanoForth Virtual Machine class

Function Documentation

_nest()

void N4VM::_nest

(

IU

xt

)

‍reset virtual machine

‍opcode execution unit i.e. inner interpreter

‍walk through instruction sequences

< fetch instruction

< masked opcode

‍branching opcodes?

‍primitive word?

‍handle number (1-byte literal)

‍walk through instruction sequences

< fetch instruction

< masked opcode

‍branching opcodes?

‍primitive word?

‍handle number (1-byte literal)

_init()

void N4VM::_init

(

)

• forward declaration

• reset return stack pointer

• reset data stack pointer

• init interrupt handler

• reload EEPROM and reset assembler

• check autorun addr has been setup? (see SEX)

• execute last saved colon word in EEPROM

_dump()

void N4VM::_dump	(	IU	p0,
		U16	sz0
	)

_immediate()

void N4VM::_immediate

(

U16

op

)

‍immediate word handler

‍compiler

• : (COLON), switch into compile mode (for new word)

• VAL, create new constant

• VAR, create new variable

‍interrupt handlers

• PCI, create a pin change interrupt handler

• TMI, create a timer interrupt handler

< tmp = ISR slot#

• period in multiply of 10ms

‍system

• SEX - save/execute (autorun)

• SAV

• LD

‍dicionary debugging

• FGT, rollback word created

• DMP, memory dump

• SEE

• WRD

‍numeric radix

• DEC

• HEX

• BYE, restart

_clock()

void N4VM::_clock

(

)

_dplus()

void N4VM::_dplus

(

)

_dminus()

void N4VM::_dminus

(

)

_dneg()

void N4VM::_dneg

(

)

_invoke()

IU N4VM::_invoke	(	U8	op,
		IU	xt = 0
	)

‍invoke a built-in opcode Note: computed goto takes extra 128-bytes for ~5% faster

‍stack ops

‍Bit-wise ops

‍ALU ops

‍Logical ops

‍IO ops

‍Compiler ops

‍Double ops

‍Arduino Specific ops

‍meta programming (for advance users)

setup()

void N4VM::setup	(	const char *	code,
		Stream &	io,
		U8	ucase
	)

‍constructor and initializer

• install embedded Forth code

• set IO stream pointer (static member, shared with N4ASM)

• set case sensitiveness

• set radix = 10

• init VM

Parameters

code	preload Forth code
io	IO stream
ucase	case sensitiveness

push()

void N4VM::push

(

int

v

)

‍VM proxy functions

pop()

int N4VM::pop

(

)

serv_isr()

void N4VM::serv_isr

(

)

interrupt service routine

‍virtual machine interrupt service routine

outer()

void N4VM::outer

(

)

outer-interpreter

‍virtual machine execute single step (outer interpreter)

Returns

1: more token(s) in input buffer
0: buffer empty (yield control back to hardware)

‍console ok prompt if tib is empty

‍get a token from console

‍parse action from token (keep opcode in tmp)

‍immediate words,

‍execute colon word (user defined)

‍execute primitive built-in word,

‍push a number (literal) to stack top,

‍extended words, not implemented yet

‍or, error (unknown action)