Data Structures
class	areg
	operand of this type can only be an analogue register More...

Functions
	pe_rpix ()
	reset PIX (the photodiode) More...

	pe_rpix (areg a1, areg a2)
	read the image from PIX in to AREGs, and reset PIX More...

areg	pe_mov (areg a1)
	make a copy of an AREG More...

areg	pe_add (areg a1, areg a2)
	add two AREGs More...

areg	pe_sub (areg a1, areg a2)
	subtract two AREGs More...

areg	pe_neg (areg a1)
	invert the polarity of AREG and copy to another AREG More...

areg	pe_abs (areg a1)
	take the absolute value of an AREG and copy to another AREG More...

	pe_div (areg a1, areg a2, areg a3)
	divide (by half) an AREG into two AREGs More...

areg	pe_in (r_int v)
	set an analogue register for all pe with a value More...

areg	pe_north (areg a1)
	copy the AREG of the north neighbouring PE More...

areg	pe_east (areg a1)
	copy the AREG of the east neighbouring PE More...

areg	pe_west (areg a1)
	copy the AREG of the west neighbouring PE More...

areg	pe_south (areg a1)
	copy the AREG of the south neighbouring PE More...

Detailed Description

Author: Jianing Chen

Function Documentation

pe_rpix ( )

reset PIX (the photodiode)

As this macro clears the light accumulated on the photodiode, it also marks the beginning of a new exposure period.

pe_rpix	(	areg	a1,
		areg	a2
	)

read the image from PIX in to AREGs, and reset PIX

Parameters

a1	stores the image using a range of [0,-127]
a2	stores the image using a range of [-127,-127]

Both of the stored images have positive polarity, but they have different ranges.

For a1, the theoretical range is 0 to 127 from darkest to brightest.

For a2, the theoretical range is -127 to 127 from darkest to brightest.

Example Usage:

The first thing to do in a new frame is likely to be:

1 pe.rpix(B,C)

areg pe_mov ( areg a1 )

make a copy of an AREG

Parameters

a1	the AREG to be copied

Returns: the destination AREG to place the copy

Example Usage:

1 A = pe.mov(B)

areg pe_add	(	areg	a1,
		areg	a2
	)

add two AREGs

Parameters

a1	first AREG
a2	second AREG

Returns: the result of "a1 + a2"

Example Usage:

The following line arithmetically achieves "A = B + C":

1 A = pe.add(B,C)

The following line arithmetically achieves "B = B + C":

1 pe.add(B,C)

areg pe_sub	(	areg	a1,
		areg	a2
	)

subtract two AREGs

Parameters

a1	the AREG to subtract from
a2	the subtracted AREG

Returns: the result of (a1 - a2)

Example Usage:

The following line arithmetically achieves "A = B - C":

1 A = pe.sub(B,C)

The following line arithmetically achieves "B = B - C":

1 pe.sub(B,C)

areg pe_neg ( areg a1 )

invert the polarity of AREG and copy to another AREG

Parameters

a1	the source AREG

Returns: the resulted copy

The copy step in this macro is free of offset error.

Example Usage:

The following line arithmetically achieves "A = -B":

1 A = pe.neg(B)

areg pe_abs ( areg a1 )

take the absolute value of an AREG and copy to another AREG

Parameters

a1	the source AREG

Returns: the resulted copy

The copy step in this macro is free of offset error.

Example Usage:

The following line arithmetically achieves "A = |B|":

1 A = pe.abs(B)

pe_div	(	areg	a1,
		areg	a2,
		areg	a3
	)

divide (by half) an AREG into two AREGs

Parameters

a1	the source AREG
a2	the first half of the result
a3	the second half of the result

The copy step in this macro is free of offset error. Note, the two results may not be equal, a small mismatch error may still exist despite a compensation procedure being applied within this macro.

Example Usage:

The following line arithmetically achieves "B = A/2, C = A/2":

1 pe.div(A,B,C)

areg pe_in ( r_int v )

set an analogue register for all pe with a value

Parameters

v	a value with a range of [-128,127]

Returns: the analogue register to store the value

The value used is an signed 8-bit integer. Thus, value warp will occur when overflow or underflow happens. For example, "in(128)" is essentially "in(-128)" and "in(-129)" is "in(127)".

Example Usage:

Filling register A with 50:

1 A = pe.in(50)

Filling register A with a value read from a slider on the host:

1 s0 = usb.slider(my_slider_1)

2 A = pe.in(s0)

areg pe_north ( areg a1 )

copy the AREG of the north neighbouring PE

Parameters

a1	the target AREG of the north neighbouring PE

Returns: the value analogue register

Example Usage:

Copy B of the north neighbour to the B in this PE:

1 B = pe.north(B)

areg pe_east ( areg a1 )

copy the AREG of the east neighbouring PE

Parameters

a1	the target AREG of the east neighbouring PE

Returns: the value analogue register

areg pe_west ( areg a1 )

copy the AREG of the west neighbouring PE

Parameters

a1	the target AREG of the west neighbouring PE

Returns: the value analogue register

areg pe_south ( areg a1 )

copy the AREG of the south neighbouring PE

Parameters

a1	the target AREG of the south neighbouring PE

Returns: the value analogue register

Data Structures

Functions

Detailed Description

Function Documentation