Mike at 11:44, 16 March 2010

2010-03-16T11:44:44Z

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= Introduction =
This sample application demonstrates the I2C communication between EM-X270 and CAT9555 GPIO extender located on EB-X270. The CAT9555 datasheet is available at: [http://www.onsemi.com/pub_link/Collateral/CAT9555-D.PDF 9555.pdf].

The I2C sample is located in the EM-X270 run-time image package in the {{Filename|\x270-em-wince6-img\Demo Applications\I2CSample}} folder.

= I2C Sample =
The sample application performs the following actions:
* Read the configuration registers. Normal mode clock is used.
* Write registers. Set all pins, except for pin 0, to inputs.
* Read the registers to verify write.
* Read the output port register.
* Write the output port register. Configure pin 1 on P9 connector on the EB-X270 to be low.

= Connecting Custom Device =
I2C physical interface:
{| cellpadding="3" border="1" style="border: 1px solid rgb(85, 85, 85); border-collapse: collapse;"
|-
| '''Signal Name'''
| '''EB-X270'''
| '''EM-X270'''
|-
| SCL
| Pin 19 of U5
| Pin 132 on the CAMI
|-
| SDA
| Pin 20 of U5
| Pin 136 on the CAMI
|}

= I2C Driver API =
The Windows CE demo image includes an I2C driver that allows interaction with I2C devices.
The I2C driver is a stream driver that may be accessed using the "I2C" prefix.
The following pseudo code describes the driver’s algorithm:
<pre>
1. Set the clock speed according to mClkSpeed
2. FOR i=0 TO i=mTransaction-1
IF (mOpCode[i] == I2C_OPCODE_WRITE) THEN
FOR j=0 TO mTransLen[i]-1
write mBuffer[mBufferOffset[i]+j] to the bus.
ELSE IF (mOpCode[i] == I2C_OPCODE_READ) THEN
FOR j=0 TO mTransLen[i]-1
read mTransLen[i] bytes from the bus into mBuffer[mBufferOffset[i]+j]
ELSE “Fail – OpCode not supported”
</pre>

== Data Types ==
{{Enum| HeadLevel = ==== | Enumname = PXA_I2C_SPEED_T |
Description = |
Field1 = PXA_I2C_FAST_SPEED - use 400KHz clock|
Field2 = PXA_I2C_NORMAL_SPEED - use 100KHz clock|
Field3 = |
Field4 = |
Remarks =
}}
{{Enum| HeadLevel = ==== | Enumname = PXA_I2C_OPERATION_CODE |
Description = |
Field1 = I2C_OPCODE_READ |
Field2 = I2C_OPCODE_WRITE |
Field3 = |
Field4 = |
Remarks =
}}
{{Struct| HeadLevel = ==== | Structname = I2CTRANS |
Description = |
Field1 = DWORD mTransactions |
Fieldexp1 = Number f transactions to perform|
Field2 = [[#PXA_I2C_SPEED_T|PXA_I2C_SPEED_T]] mClkSpeed|
Fieldexp2 = |
Field3 = UCHAR mDeviceAddr|
Fieldexp3 = 7 bit I2C address|
Field4 = [[#PXA_I2C_OPERATION_CODE|PXA_I2C_OPERATION_CODE]] *mOpCode|
Fieldexp4 = |
Field5 = DWORD *mBufferOffset|
Fieldexp5 = The offset for the data in the array for each transaction|
Field6 = DWORD *mTransLen|
Fieldexp6 = The length of each transaction|
Field7 = DWORD mErrorCode|
Fieldexp7 = |
Field8 = UCHAR *mBuffer|
Fieldexp8 = The buffer with the data for all the transactions|
MoreFields = |
Remarks = |
}}
== Functions ==
{{APIEx | HeadLevel = ==== | Signature = HANDLE I2CUserOpen() |
Description = Opens an instance of the I2C Driver. |
Return = Returns a handle that should be used to access the driver. Nonzero indicates success. |
Param1 = |
Param2 = |
Param3 = |
Param4 = |
Remarks = }}

{{APIEx | HeadLevel = ==== | Signature = void I2CUserClose(HANDLE hDevice) |
Description = Closes the driver handle |
Return = |
Param1 = *hDevice - Handle to an open driver instance|
Param2 = |
Param3 = |
Param4 = |
Remarks = }}

{{APIEx | HeadLevel = ==== | Signature = void I2CUserTransact(HANDLE hDevice, [[#I2CTRANS|I2CTRANS]]* pTrans) |
Description = Perform the I2C transaction |
Return = TRUE on success|
Param1 = *hDevice - Handle to an open driver instance|
Param2 = *pTrans |
Param3 = |
Param4 = |
Remarks = }}

[[Category:Windows CE|I2C Sample ]]
[[Category:EM-X270|WinCE: I2C Sample ]]

EM-X270: WinCE: I2C Sample - Revision history

Mike at 11:44, 16 March 2010