avr: moved COM and COMPROTO defs and routines into dedicated files.

avr/flash.asm

@@ -174,6 +174,63 @@ wait:                ; wait for possibly previous SPM to complete
   ret
 
 
+
+; ---------------------------------------------------------------------------
+; flashReadEepromIncr
+;
+; Read a byte from EEPROM (see example in ATtiny24/44/84 manual p.19).
+;
+; IN:
+; - X: EEPROM Address to read from
+; OUT:
+; - R16: byte read
+; - X: EEPROM Address incremented
+; MODIFIED REGISTERS: R16
+
+flashReadEepromIncr:
+  sbic EECR, EEPE          ; wait for previous write to complete (if any)
+    rjmp flashReadEepromIncr
+  out EEARH, xh            ; set EEPROM address
+  out EEARL, xl
+  sbi EECR, EERE           ; start EEPROM read by writing EERE
+  in r16, EEDR             ; read data from data register
+  adiw xh:xl, 1
+  ret
+
+
+
+; ---------------------------------------------------------------------------
+; flashReadUid
+;
+; Read UID from EEPROM.
+;
+; IN:
+; OUT:
+; - R18:R19:R20:R21: UID
+; REGS: R16, X
+
+flashReadUid:
+  in r15, SREG
+  push r15
+    cli
+    ldi xl, LOW(EEPROM_OFFS_UUID)
+    ldi xh, HIGH(EEPROM_OFFS_UUID)
+    rcall flashReadEepromIncr ; (R16)
+    mov r18, r16
+    rcall flashReadEepromIncr ; (R16)
+    mov r19, r16
+    rcall flashReadEepromIncr ; (R16)
+    mov r20, r16
+    rcall flashReadEepromIncr ; (R16)
+    mov r21, r16
+  pop r15
+  out SREG, r15
+  ret
+
+
+
+
+
 FLASH_END:
 .equ MODULE_SIZE_FLASH = FLASH_END-FLASH_BEGIN