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authorDean <Dean@d5102386-fcda-11dd-9fdb-3debd5008f28>2011-09-21 06:35:28 +0000
committerDean <Dean@d5102386-fcda-11dd-9fdb-3debd5008f28>2011-09-21 06:35:28 +0000
commitffc451fbd9631b4e0a45bce36dda3e34facee2de (patch)
treecc4e8c2d4fb4b519f80c87cc13c32cdafd4c52d8 /LUFA/Drivers/Peripheral/AVR8/TWI_AVR8.c
parent44e3311de4c0d12b228bce55edc4ceff690d4f91 (diff)
Add LUFA-111009-BETA tag.LUFA-111009-BETA
git-svn-id: http://lufa-lib.googlecode.com/svn/tags/LUFA-111009-BETA@1929 d5102386-fcda-11dd-9fdb-3debd5008f28
Diffstat (limited to 'LUFA/Drivers/Peripheral/AVR8/TWI_AVR8.c')
-rw-r--r--LUFA/Drivers/Peripheral/AVR8/TWI_AVR8.c63
1 files changed, 49 insertions, 14 deletions
diff --git a/LUFA/Drivers/Peripheral/AVR8/TWI_AVR8.c b/LUFA/Drivers/Peripheral/AVR8/TWI_AVR8.c
index 2f65921c..d6db37d6 100644
--- a/LUFA/Drivers/Peripheral/AVR8/TWI_AVR8.c
+++ b/LUFA/Drivers/Peripheral/AVR8/TWI_AVR8.c
@@ -97,34 +97,69 @@ uint8_t TWI_StartTransmission(const uint8_t SlaveAddress,
}
}
+bool TWI_SendByte(const uint8_t Byte)
+{
+ TWDR = Byte;
+ TWCR = ((1 << TWINT) | (1 << TWEN));
+ while (!(TWCR & (1 << TWINT)));
+
+ return ((TWSR & TW_STATUS_MASK) == TW_MT_DATA_ACK);
+}
+
+bool TWI_ReceiveByte(uint8_t* const Byte,
+ const bool LastByte)
+{
+ uint8_t TWCRMask;
+
+ if (LastByte)
+ TWCRMask = ((1 << TWINT) | (1 << TWEN));
+ else
+ TWCRMask = ((1 << TWINT) | (1 << TWEN) | (1 << TWEA));
+
+ TWCR = TWCRMask;
+ while (!(TWCR & (1 << TWINT)));
+ *Byte = TWDR;
+
+ uint8_t Status = (TWSR & TW_STATUS_MASK);
+
+ return ((LastByte) ? (Status == TW_MR_DATA_NACK) : (Status == TW_MR_DATA_ACK));
+}
+
uint8_t TWI_ReadPacket(const uint8_t SlaveAddress,
const uint8_t TimeoutMS,
const uint8_t* InternalAddress,
- const uint8_t InternalAddressLen,
+ uint8_t InternalAddressLen,
uint8_t* Buffer,
uint8_t Length)
{
uint8_t ErrorCode;
- if ((ErrorCode = TWI_WritePacket(SlaveAddress, TimeoutMS, InternalAddress, InternalAddressLen,
- NULL, 0)) != TWI_ERROR_NoError)
- {
- return ErrorCode;
- }
-
- if ((ErrorCode = TWI_StartTransmission((SlaveAddress & TWI_DEVICE_ADDRESS_MASK) | TWI_ADDRESS_READ,
- TimeoutMS)) == TWI_ERROR_NoError)
+ if ((ErrorCode = TWI_StartTransmission((SlaveAddress & TWI_DEVICE_ADDRESS_MASK) | TWI_ADDRESS_WRITE,
+ TimeoutMS)) == TWI_ERROR_NoError)
{
- while (Length--)
+ while (InternalAddressLen--)
{
- if (!(TWI_ReceiveByte(Buffer++, (Length == 0))))
- {
+ if (!(TWI_SendByte(*(InternalAddress++))))
+ {
ErrorCode = TWI_ERROR_SlaveNAK;
break;
}
}
- TWI_StopTransmission();
+ if ((ErrorCode = TWI_StartTransmission((SlaveAddress & TWI_DEVICE_ADDRESS_MASK) | TWI_ADDRESS_READ,
+ TimeoutMS)) == TWI_ERROR_NoError)
+ {
+ while (Length--)
+ {
+ if (!(TWI_ReceiveByte(Buffer++, (Length == 0))))
+ {
+ ErrorCode = TWI_ERROR_SlaveNAK;
+ break;
+ }
+ }
+
+ TWI_StopTransmission();
+ }
}
return ErrorCode;
@@ -145,7 +180,7 @@ uint8_t TWI_WritePacket(const uint8_t SlaveAddress,
while (InternalAddressLen--)
{
if (!(TWI_SendByte(*(InternalAddress++))))
- {
+ {
ErrorCode = TWI_ERROR_SlaveNAK;
break;
}