[sigrok-dumps.git] / i2c / microchip_mcp23017 / README.md

-------------------------------------------------------------------------------
Microchip MCP23017 I/O expander with I2C interface
-------------------------------------------------------------------------------

This is a set of example captures of the MCP23017 16-bit I/O expander with
an I2C interface. For details see the MCP23017/MCP23S17 datasheet which is
titled "16-Bit I/O Expander with Serial Interface":

  http://ww1.microchip.com/downloads/en/DeviceDoc/20001952C.pdf


Logic analyzer setup
--------------------

The logic analyzer used was a Saleae clone (samplerate 1MHz). In addition
to the I2C datalines, 6 output pins are captured too.

The host was a Raspberry Pi using Python to access the I2C port. The bitrate
decreased after a few 100ms.

  Probe       MCP23017
  -------------------
  0           A0
  1           A1
  2           A2
  3           B0 / A3
  4           B1 / A4
  5           B2 / A5
  6           SDA
  7           SCL


mcp23017_counter_a_write.sr
---------------------------

Count the Registers OLATA ascending. The lowest 6 bits of the Output A Port
are captured too (A0 - A5).


mcp23017_counter_init_ab_write.sr
---------------------------------

Reset all registers, then count the registers OLATA ascending and OLATB
descending. Both registers are set using one word write operation. The
lowest 3 bits of both output ports are captured too (A0 - A2, B0 - B2).


mcp23017_counter_init_ab_write_read.sr
-------------------------------------

Reset all registers, then count the registers OLATA ascending and OLATB
descending. Both registers are set and read using one word write operations.
The lowest 3 bits of both output ports are captured too (A0 - A2, B0 - B2).
Commit	Line	Data
91e85d43 BO	1	-------------------------------------------------------------------------------
	2	Microchip MCP23017 I/O expander with I2C interface
	3	-------------------------------------------------------------------------------
	4
	5	This is a set of example captures of the MCP23017 16-bit I/O expander with
	6	an I2C interface. For details see the MCP23017/MCP23S17 datasheet which is
	7	titled "16-Bit I/O Expander with Serial Interface":
	8
	9	http://ww1.microchip.com/downloads/en/DeviceDoc/20001952C.pdf
	10
	11
	12	Logic analyzer setup
	13	--------------------
	14
	15	The logic analyzer used was a Saleae clone (samplerate 1MHz). In addition
	16	to the I2C datalines, 6 output pins are captured too.
	17
	18	The host was a Raspberry Pi using Python to access the I2C port. The bitrate
	19	decreased after a few 100ms.
	20
	21	Probe MCP23017
	22	-------------------
	23	0 A0
	24	1 A1
	25	2 A2
	26	3 B0 / A3
	27	4 B1 / A4
	28	5 B2 / A5
	29	6 SDA
	30	7 SCL
	31
	32
	33	mcp23017_counter_a_write.sr
	34	---------------------------
	35
	36	Count the Registers OLATA ascending. The lowest 6 bits of the Output A Port
	37	are captured too (A0 - A5).
	38
	39
	40	mcp23017_counter_init_ab_write.sr
	41	---------------------------------
	42
	43	Reset all registers, then count the registers OLATA ascending and OLATB
	44	descending. Both registers are set using one word write operation. The
	45	lowest 3 bits of both output ports are captured too (A0 - A2, B0 - B2).
	46
	47
	48	mcp23017_counter_init_ab_write_read.sr
	49	-------------------------------------
	50
	51	Reset all registers, then count the registers OLATA ascending and OLATB
	52	descending. Both registers are set and read using one word write operations.
	53	The lowest 3 bits of both output ports are captured too (A0 - A2, B0 - B2).