Oops - PDI handshake delay was too long, causing the device's /RESET functionality...

[pub/USBasp.git] / Projects / AVRISP-MKII / Lib / XPROG / XPROGTarget.c

diff --git a/Projects/AVRISP-MKII/Lib/XPROG/XPROGTarget.c b/Projects/AVRISP-MKII/Lib/XPROG/XPROGTarget.c
index 05d5ec9..843bf5a 100644 (file)
--- a/Projects/AVRISP-MKII/Lib/XPROG/XPROGTarget.c
+++ b/Projects/AVRISP-MKII/Lib/XPROG/XPROGTarget.c
@@ -71,7 +71,7 @@ ISR(TIMER1_COMPA_vect, ISR_BLOCK)
                  return;\r
        \r
                /* Shift in the bit one less than the frame size in position, so that the start bit will eventually\r
-                * be discarded leaving the data to be byte-aligned for quick access */\r
+                * be discarded leaving the data to be byte-aligned for quick access (subtract 9 as we are ORing to the MSB) */\r
                if (BITBANG_PDIDATA_PIN & BITBANG_PDIDATA_MASK)\r
                  ((uint8_t*)&SoftUSART_Data)[1] |= (1 << (BITS_IN_USART_FRAME - 9));\r
 \r
@@ -96,7 +96,7 @@ ISR(TIMER1_COMPA_vect, ISR_BLOCK)
 }\r
 \r
 /** ISR to manage the TPI software USART when bit-banged TPI USART mode is selected. */\r
-ISR(TIMER1_COMPB_vect, ISR_BLOCK)\r
+ISR(TIMER1_CAPT_vect, ISR_BLOCK)\r
 {\r
        /* Toggle CLOCK pin in a single cycle (see AVR datasheet) */\r
        BITBANG_TPICLOCK_PIN |= BITBANG_TPICLOCK_MASK;\r
@@ -117,7 +117,7 @@ ISR(TIMER1_COMPB_vect, ISR_BLOCK)
                  return;\r
        \r
                /* Shift in the bit one less than the frame size in position, so that the start bit will eventually\r
-                * be discarded leaving the data to be byte-aligned for quick access */\r
+                * be discarded leaving the data to be byte-aligned for quick access (subtract 9 as we are ORing to the MSB) */\r
                if (BITBANG_TPIDATA_PIN & BITBANG_TPIDATA_MASK)\r
                 ((uint8_t*)&SoftUSART_Data)[1] |= (1 << (BITS_IN_USART_FRAME - 9));\r
 \r
@@ -152,7 +152,8 @@ void XPROGTarget_EnableTargetPDI(void)
        DDRD |=  (1 << 5) | (1 << 3);\r
        DDRD &= ~(1 << 2);\r
        \r
-       /* Set DATA line high for at least 90ns to disable /RESET functionality */\r
+       /* Set DATA line high for at least 90ns to disable /RESET functionality (note: too long will enable it again,\r
+        * so a fixed number of NOPs are used here */\r
        PORTD |= (1 << 3);\r
        asm volatile ("NOP"::);\r
        asm volatile ("NOP"::);\r
@@ -167,7 +168,8 @@ void XPROGTarget_EnableTargetPDI(void)
        BITBANG_PDIDATA_DDR  |= BITBANG_PDIDATA_MASK;\r
        BITBANG_PDICLOCK_DDR |= BITBANG_PDICLOCK_MASK;\r
        \r
-       /* Set DATA line high for at least 90ns to disable /RESET functionality */\r
+       /* Set DATA line high for at least 90ns to disable /RESET functionality (note: too long will enable it again,\r
+        * so a fixed number of NOPs are used here */\r
        BITBANG_PDIDATA_PORT |= BITBANG_PDIDATA_MASK;\r
        asm volatile ("NOP"::);\r
        asm volatile ("NOP"::);\r
@@ -188,11 +190,10 @@ void XPROGTarget_EnableTargetTPI(void)
 {\r
        IsSending = false;\r
 \r
-       /* Set /RESET line low for at least 90ns to enable TPI functionality */\r
+       /* Set /RESET line low for at least 400ns to enable TPI functionality */\r
        AUX_LINE_DDR  |=  AUX_LINE_MASK;\r
        AUX_LINE_PORT &= ~AUX_LINE_MASK;\r
-       asm volatile ("NOP"::);\r
-       asm volatile ("NOP"::);\r
+       _delay_ms(1);\r
 \r
 #if defined(XPROG_VIA_HARDWARE_USART)\r
        /* Set Tx and XCK as outputs, Rx as input */\r
@@ -212,10 +213,10 @@ void XPROGTarget_EnableTargetTPI(void)
        /* Set DATA line high for idle state */\r
        BITBANG_TPIDATA_PORT |= BITBANG_TPIDATA_MASK;\r
 \r
-       /* Fire timer capture channel B ISR to manage the software USART */\r
-       OCR1B   = BITS_BETWEEN_USART_CLOCKS;\r
-       TCCR1B  = (1 << WGM12) | (1 << CS10);\r
-       TIMSK1  = (1 << OCIE1B);\r
+       /* Fire timer capture channel ISR to manage the software USART */\r
+       ICR1    = BITS_BETWEEN_USART_CLOCKS;\r
+       TCCR1B  = (1 << WGM13) | (1 << WGM12) | (1 << CS10);\r
+       TIMSK1  = (1 << ICIE1);\r
 #endif\r
 \r
        /* Send two BREAKs of 12 bits each to enable TPI interface (need at least 16 idle bits) */\r
@@ -307,7 +308,7 @@ void XPROGTarget_SendByte(const uint8_t Byte)
        uint16_t NewUSARTData = ((1 << 11) | (1 << 10) | (0 << 9) | ((uint16_t)Byte << 1) | (0 << 0));\r
 \r
        /* Compute Even parity - while a bit is still set, chop off lowest bit and toggle parity bit */\r
-       uint8_t ParityData    = Byte;\r
+       uint8_t ParityData = Byte;\r
        while (ParityData)\r
        {\r
                NewUSARTData ^= (1 << 9);\r