From e5166fb9228eb96e9e64a13daec68dbaab21e762 Mon Sep 17 00:00:00 2001
From: Sandeep Mistry <s.mistry@arduino.cc>
Date: Mon, 18 Jan 2016 17:42:05 -0500
Subject: [PATCH] Use TX buffer for slave writes, empty on master read mode +
DRDY IRQ
---
cores/arduino/SERCOM.cpp | 5 +---
libraries/Wire/Wire.cpp | 59 ++++++++++++++++++++--------------------
2 files changed, 30 insertions(+), 34 deletions(-)
diff --git a/cores/arduino/SERCOM.cpp b/cores/arduino/SERCOM.cpp
index d0fa4db8..3447d9dd 100644
--- a/cores/arduino/SERCOM.cpp
+++ b/cores/arduino/SERCOM.cpp
@@ -557,11 +557,8 @@ bool SERCOM::sendDataSlaveWIRE(uint8_t data)
//Send data
sercom->I2CS.DATA.bit.DATA = data;
- //Wait data transmission successful
- while(!sercom->I2CS.INTFLAG.bit.DRDY);
-
//Problems on line? nack received?
- if(sercom->I2CS.STATUS.bit.RXNACK)
+ if(!sercom->I2CS.INTFLAG.bit.DRDY || sercom->I2CS.STATUS.bit.RXNACK)
return false;
else
return true;
diff --git a/libraries/Wire/Wire.cpp b/libraries/Wire/Wire.cpp
index 7857a3d0..0326bf68 100644
--- a/libraries/Wire/Wire.cpp
+++ b/libraries/Wire/Wire.cpp
@@ -153,27 +153,15 @@ uint8_t TwoWire::endTransmission()
size_t TwoWire::write(uint8_t ucData)
{
- if(sercom->isMasterWIRE())
+ // No writing, without begun transmission or a full buffer
+ if ( !transmissionBegun || txBuffer.isFull() )
{
- // No writing, without begun transmission or a full buffer
- if ( !transmissionBegun || txBuffer.isFull() )
- {
- return 0 ;
- }
-
- txBuffer.store_char( ucData ) ;
-
- return 1 ;
- }
- else
- {
- if(sercom->sendDataSlaveWIRE( ucData ))
- {
- return 1;
- }
+ return 0 ;
}
- return 0;
+ txBuffer.store_char( ucData ) ;
+
+ return 1 ;
}
size_t TwoWire::write(const uint8_t *data, size_t quantity)
@@ -246,9 +234,9 @@ void TwoWire::onService(void)
if(sercom->isMasterReadOperationWIRE()) //Is a request ?
{
- // wait for data ready flag,
- // before calling request callback
- while(!sercom->isDataReadyWIRE());
+ txBuffer.clear();
+
+ transmissionBegun = true;
//Calling onRequestCallback, if exists
if(onRequestCallback)
@@ -257,18 +245,29 @@ void TwoWire::onService(void)
}
}
}
- else if(sercom->isDataReadyWIRE()) //Received data
+ else if(sercom->isDataReadyWIRE())
{
- if (rxBuffer.isFull()) {
- sercom->prepareNackBitWIRE();
- } else {
- //Store data
- rxBuffer.store_char(sercom->readDataWIRE());
+ if (sercom->isMasterReadOperationWIRE())
+ {
+ uint8_t c = 0xff;
- sercom->prepareAckBitWIRE();
- }
+ if( txBuffer.available() ) {
+ c = txBuffer.read_char();
+ }
- sercom->prepareCommandBitsWire(0x03);
+ transmissionBegun = sercom->sendDataSlaveWIRE(c);
+ } else { //Received data
+ if (rxBuffer.isFull()) {
+ sercom->prepareNackBitWIRE();
+ } else {
+ //Store data
+ rxBuffer.store_char(sercom->readDataWIRE());
+
+ sercom->prepareAckBitWIRE();
+ }
+
+ sercom->prepareCommandBitsWire(0x03);
+ }
}
}
}
--
GitLab