Document the PDI programming routines implemented so far in the AVRISP project. Add...

[pub/USBasp.git] / Projects / AVRISP / Lib / PDIProtocol.c

diff --git a/Projects/AVRISP/Lib/PDIProtocol.c b/Projects/AVRISP/Lib/PDIProtocol.c
index c919561..2ed3ff2 100644 (file)
--- a/Projects/AVRISP/Lib/PDIProtocol.c
+++ b/Projects/AVRISP/Lib/PDIProtocol.c
@@ -30,6 +30,8 @@
 \r
 #if defined(ENABLE_XPROG_PROTOCOL)\r
 \r
+#warning PDI Programming Protocol support is incomplete and not currently suitable for use.\r
+\r
 /** \file\r
  *\r
  *  PDI Protocol handler, to process V2 Protocol wrapped PDI commands used in Atmel programmer devices.\r
@@ -61,6 +63,9 @@ void PDIProtocol_XPROG_SetMode(void)
        Endpoint_ClearIN();     \r
 }\r
 \r
+/** Handler for the CMD_XPROG command, which wraps up XPROG commands in a V2 wrapper which need to be\r
+ *  removed and processed so that the underlying XPROG command can be handled.\r
+ */\r
 void PDIProtocol_XPROG_Command(void)\r
 {\r
        uint8_t XPROGCommand = Endpoint_Read_Byte();\r
@@ -74,7 +79,7 @@ void PDIProtocol_XPROG_Command(void)
                        PDIProtocol_LeaveXPROGMode();\r
                        break;\r
                case XPRG_CMD_ERASE:\r
-                       PDIProtocol_EraseChip();\r
+                       PDIProtocol_Erase();\r
                        break;\r
                case XPRG_CMD_WRITE_MEM:\r
                        PDIProtocol_WriteMemory();\r
@@ -91,6 +96,7 @@ void PDIProtocol_XPROG_Command(void)
        }\r
 }\r
 \r
+/** Handler for the XPROG ENTER_PROGMODE command to establish a PDI connection with the attached device. */\r
 static void PDIProtocol_EnterXPROGMode(void)\r
 {\r
        uint8_t ReturnStatus = XPRG_ERR_OK;\r
@@ -101,22 +107,20 @@ static void PDIProtocol_EnterXPROGMode(void)
        PDIDATA_LINE_DDR  |= PDIDATA_LINE_MASK;\r
        PDICLOCK_LINE_DDR |= PDICLOCK_LINE_MASK;\r
        \r
+       /* Must hold DATA line high for at least 90nS to enable PDI interface */\r
        PDIDATA_LINE_PORT |= PDIDATA_LINE_MASK;\r
-\r
        _delay_us(1);\r
        \r
+       /* Toggle CLOCK line 16 times within 100uS of the original 90nS timeout to keep PDI interface enabled */\r
        for (uint8_t i = 0; i < 16; i++)\r
-       {\r
-               PDICLOCK_LINE_PORT ^= PDICLOCK_LINE_MASK;\r
-               PDICLOCK_LINE_PORT ^= PDICLOCK_LINE_MASK;\r
-       }\r
-               \r
-       static const uint8_t NVMKey[8] = {0x12, 0x89, 0xAB, 0x45, 0xCD, 0xD8, 0x88, 0xFF};\r
+         TOGGLE_PDI_CLOCK;\r
        \r
+       /* Enable access to the XPROG NVM bus by sending the documented NVM access key to the device */\r
        PDITarget_SendByte(PDI_CMD_KEY);        \r
        for (uint8_t i = 0; i < 8; i++)\r
-         PDITarget_SendByte(NVMKey[i]);\r
+         PDITarget_SendByte(PDI_NVMENABLE_KEY[i]);\r
 \r
+       /* Read out the STATUS register to check that NVM access was successfully enabled */\r
        PDITarget_SendByte(PDI_CMD_LDCS | PD_STATUS_REG);       \r
        if (!(PDITarget_ReceiveByte() & PDI_STATUS_NVM))\r
          ReturnStatus = XPRG_ERR_FAILED;\r
@@ -127,14 +131,19 @@ static void PDIProtocol_EnterXPROGMode(void)
        Endpoint_ClearIN();\r
 }\r
 \r
+/** Handler for the XPROG LEAVE_PROGMODE command to terminate the PDI programming connection with\r
+ *  the attached device.\r
+ */\r
 static void PDIProtocol_LeaveXPROGMode(void)\r
 {\r
        Endpoint_ClearOUT();\r
        Endpoint_SetEndpointDirection(ENDPOINT_DIR_IN);\r
        \r
+       /* Set DATA and CLOCK lines to inputs */\r
        PDIDATA_LINE_DDR   &= ~PDIDATA_LINE_MASK;\r
        PDICLOCK_LINE_DDR  &= ~PDICLOCK_LINE_MASK;\r
-\r
+       \r
+       /* Tristate DATA and CLOCK lines */\r
        PDIDATA_LINE_PORT  &= ~PDIDATA_LINE_MASK;\r
        PDICLOCK_LINE_PORT &= ~PDICLOCK_LINE_MASK;\r
        \r
@@ -144,7 +153,8 @@ static void PDIProtocol_LeaveXPROGMode(void)
        Endpoint_ClearIN();\r
 }\r
 \r
-static void PDIProtocol_EraseChip(void)\r
+/** Handler for the XPRG ERASE command to erase a specific memory address space in the attached device. */\r
+static void PDIProtocol_Erase(void)\r
 {\r
        uint8_t ReturnStatus = XPRG_ERR_OK;\r
 \r
@@ -167,6 +177,7 @@ static void PDIProtocol_EraseChip(void)
        Endpoint_ClearIN();     \r
 }\r
 \r
+/** Handler for the XPROG WRITE_MEMORY command to write to a specific memory space within the attached device. */\r
 static void PDIProtocol_WriteMemory(void)\r
 {\r
        uint8_t ReturnStatus = XPRG_ERR_OK;\r
@@ -196,6 +207,9 @@ static void PDIProtocol_WriteMemory(void)
        Endpoint_ClearIN();\r
 }\r
 \r
+/** Handler for the XPROG READ_MEMORY command to read data from a specific address space within the\r
+ *  attached device.\r
+ */\r
 static void PDIProtocol_ReadMemory(void)\r
 {\r
        uint8_t ReturnStatus = XPRG_ERR_OK;\r
@@ -219,23 +233,13 @@ static void PDIProtocol_ReadMemory(void)
        Endpoint_Write_Byte(CMD_XPROG);\r
        Endpoint_Write_Byte(XPRG_CMD_READ_MEM);\r
        Endpoint_Write_Byte(ReturnStatus);\r
-\r
-       // START TEMP\r
-       uint8_t ProgData[256];\r
-       for (uint16_t i = 0; i < ReadMemory_XPROG_Params.Length; i++)\r
-         ProgData[i] = i;\r
-       Endpoint_Write_Stream_LE(ProgData, ReadMemory_XPROG_Params.Length);\r
-\r
-       if (!Endpoint_IsReadWriteAllowed())\r
-       {\r
-               Endpoint_ClearIN();     \r
-               while(!(Endpoint_IsReadWriteAllowed()));\r
-       }\r
-       // END TEMP\r
        \r
        Endpoint_ClearIN();\r
 }\r
 \r
+/** Handler for the XPROG CRC command to read a specific memory space's CRC value for comparison between the\r
+ *  attached device's memory and a data set on the host.\r
+ */\r
 static void PDIProtocol_ReadCRC(void)\r
 {\r
        uint8_t ReturnStatus = XPRG_ERR_OK;\r
@@ -262,6 +266,9 @@ static void PDIProtocol_ReadCRC(void)
        Endpoint_ClearIN();     \r
 }\r
 \r
+/** Handler for the XPROG SET_PARAM command to set a PDI parameter for use when communicating with the\r
+ *  attached device.\r
+ */\r
 static void PDIProtocol_SetParam(void)\r
 {\r
        uint8_t ReturnStatus = XPRG_ERR_OK;\r