improve performance 16 pins interface

[RobTillaart]

No description provided.

[alx-uta]

@RobTillaart just had a look at the code.

I can see what you did, instead of reading or writing twice, you'll only do it once.

That's really good.

I'll run a few tests and I'll share the results.

[alx-uta]

Test results:

Software SPI

true
HWSPI: 0

SPISpeed:	1000000

time in microseconds

TEST digitalWrite(0, value):	63.38
TEST digitalWrite(pin, value):	45.69
TEST digitalRead(pin):	32.00

TEST write8(port, mask):	33.00
TEST read8(port):	34.50

TEST write16(mask):	39.50
TEST read16():	39.50

VAL1:	0
VAL8:	170
VAL16:	43690

SPISpeed:	2000000

time in microseconds

TEST digitalWrite(0, value):	60.88
TEST digitalWrite(pin, value):	61.06
TEST digitalRead(pin):	31.62

TEST write8(port, mask):	32.00
TEST read8(port):	31.50

TEST write16(mask):	31.50
TEST read16():	31.50

VAL1:	0
VAL8:	170
VAL16:	43690

SPISpeed:	4000000

time in microseconds

TEST digitalWrite(0, value):	60.88
TEST digitalWrite(pin, value):	61.06
TEST digitalRead(pin):	31.62

TEST write8(port, mask):	32.00
TEST read8(port):	31.50

TEST write16(mask):	31.50
TEST read16():	31.50

VAL1:	0
VAL8:	170
VAL16:	43690

SPISpeed:	8000000

time in microseconds

TEST digitalWrite(0, value):	60.88
TEST digitalWrite(pin, value):	61.06
TEST digitalRead(pin):	31.62

TEST write8(port, mask):	32.00
TEST read8(port):	31.50

TEST write16(mask):	31.50
TEST read16():	31.50

VAL1:	0
VAL8:	170
VAL16:	43690

Hardware SPI:

true
HWSPI: 1

SPISpeed:	1000000

time in microseconds

TEST digitalWrite(0, value):	85.87
TEST digitalWrite(pin, value):	62.94
TEST digitalRead(pin):	43.94

TEST write8(port, mask):	45.00
TEST read8(port):	47.00

TEST write16(mask):	45.00
TEST read16():	45.00

VAL1:	0
VAL8:	170
VAL16:	43690

SPISpeed:	2000000

time in microseconds

TEST digitalWrite(0, value):	56.31
TEST digitalWrite(pin, value):	56.31
TEST digitalRead(pin):	29.12

TEST write8(port, mask):	29.50
TEST read8(port):	29.50

TEST write16(mask):	23.50
TEST read16():	23.50

VAL1:	0
VAL8:	170
VAL16:	43690

SPISpeed:	4000000

time in microseconds

TEST digitalWrite(0, value):	42.63
TEST digitalWrite(pin, value):	42.63
TEST digitalRead(pin):	22.19

TEST write8(port, mask):	22.50
TEST read8(port):	22.50

TEST write16(mask):	16.50
TEST read16():	16.50

VAL1:	0
VAL8:	170
VAL16:	43690

SPISpeed:	8000000

time in microseconds

TEST digitalWrite(0, value):	35.63
TEST digitalWrite(pin, value):	35.63
TEST digitalRead(pin):	18.56

TEST write8(port, mask):	19.00
TEST read8(port):	19.00

TEST write16(mask):	13.00
TEST read16():	13.00

VAL1:	0
VAL8:	170
VAL16:	43690

SPISpeed:	10000000

time in microseconds

TEST digitalWrite(0, value):	34.31
TEST digitalWrite(pin, value):	34.31
TEST digitalRead(pin):	17.87

TEST write8(port, mask):	18.00
TEST read8(port):	18.00

TEST write16(mask):	12.00
TEST read16():	12.00

VAL1:	0
VAL8:	170
VAL16:	43690

done...

It looks really good, thx for updating it! :)