Explore I2C

README.md

@@ -7889,6 +7889,106 @@ JH7110 I2C is based on [DesignWare I2C](https://github.com/torvalds/linux/blob/m
 
 [(Search for "DesignWare DW_apb_i2c Databook")](https://www.google.com/search?q=%22DesignWare+DW_apb_i2c+Databook%22)
 
+See Page 252: "Figure 8-2: Flowchart for DW_apb_i2c Master"
+
+```text
+Write 0 to
+IC_ENABLE to
+disable
+DW_apb_i2c
+
+Program IC_CON register fields as
+required:
+1. Set IC_SLAVE_DISABLE to 1 – Slave
+ disabled
+2. Set IC_RESTART_EN to 1 – Enable
+ restart mode
+3. Set IC_10BITADDR_MASTER to 0 –
+ 7-bit addressing
+4. Set IC_10BITADDR_SLAVE to 0 – 7-bit
+ addressing
+5. Set IC_MAX_SPEED_MODE to 1 –
+ Standard mode
+6. Set IC_MASTER_MODE to 1 – Master
+ enabled
+
+Set address of
+target Slave by
+writing it to TAR
+
+Write to
+IC_SS_HCNT to
+set HIGH period
+of SCL
+
+Write to
+IC_SS_LCNT to
+set LOW period
+of SCL
+
+Write to
+IC_INTR_MASK to
+enable all
+interrupts
+
+Write to
+IC_RX_TL to
+set Rx FIFO
+threshold level
+
+Write to
+IC_TX_TL to
+set Tx FIFO
+threshold level
+
+Write 1 to
+IC_ENABLE to
+enable
+DW_apb_i2c
+
+Write to IC_DATA_CMD to
+push Write command and write data
+or Read command Tx FIFO
+
+Command is
+Write?
+
+  N:
+  RX_FULL
+  interrupt
+  asserted?
+
+    Y:
+    Read
+    IC_DATA_CMD[7:0]
+    to retrieve
+    received byte
+
+  Y:
+  TX_EMPTY
+  interrupt
+  asserted?
+
+    Y:
+    More
+    commands
+    to send?
+
+      Y:
+      Write to IC_DATA_CMD...
+
+      N:
+      Is IC_STATUS[5]
+      (MST_ACTIVITY)
+      = 0?
+
+        Y:
+        Write 0 to
+        IC_ENABLE to
+        disable
+        DW_apb_i2c  
+```
+
 Which is implemented by this NuttX Driver:
 
 - [arch/arm/src/cxd56xx/cxd56_i2c.c](https://github.com/apache/nuttx/blob/master/arch/arm/src/cxd56xx/cxd56_i2c.c)