DT USB Flags

How do these flags in DT_HID260.pbp:

Code:

---

USB_Flags          VAR BYTE BANK0

Plugged            VAR USB_Flags.0
RX_Rcvd            VAR USB_Flags.1
RX_READY          VAR USB_Flags.2
TX_READY          VAR USB_Flags.3
RX_ERROR          VAR USB_Flags.4
TX_ERROR          VAR USB_Flags.5

---

"Connect" with these pins in our programs:

Code:

---

DEFINE USB_PLUGGED    PORTD,1      ; LED indicates if USB is connected
DEFINE USB_RXrcv      PORTD,2      ;  "      "    data received from PC
DEFINE USB_RXrdy      PORTD,3      ;  "      "    data being received from PC
DEFINE USB_TXrdy      PORTD,4      ;  "      "    data being sent to PC
DEFINE USB_RXerr      PORTD,5      ;  "      "    data error from PC
DEFINE USB_TXerr      PORTD,6      ;  "      "    data error to PC

---

I looked at the datasheet and can't figure out how Port D links up with Bank 0. I'm also puzzled by the syntax PORTD,2.

Robert

That is ASM syntax.
DEFINE's are just passed to LST file, after compile.
There is no direct connection between that two pice of code.
LED's are turned on/off with macro's in DT_HID260.pbp
MACROs for LED:

Code:

---

ASM
    ifndef  USB_LEDPOLARITY          ; If LED polarity wasn't specified?
USB_LEDPOLARITY = 1                  ;  default to ON when HIGH
    endif
   
;-------------------------------   
LEDOFF  macro Port, Bit              ; -- Turn LED OFF --
    if (USB_LEDPOLARITY == 1)        ;  If LED is ON when HIGH?
        LOW?T  Port, Bit            ;    make it LOW
    else                            ;  otherwise
        HIGH?T Port, Bit            ;    make it HIGH
    endif
  endm

;------------------------------- 
LEDON  macro Port,Bit                ; -- Turn LED ON --
    if (USB_LEDPOLARITY == 1)        ;  If LED is ON when HIGH?
        HIGH?T Port, Bit            ;    make it HIGH
    else                            ;  otherwise
        LOW?T  Port, Bit            ;    make it LOW
    endif
  endm

;------------------------------- 
ifLEDisON  macro Port,Bit, Label
    if (USB_LEDPOLARITY == 1)        ; if LED is ON when HIGH
        btfsc  Port, Bit            ;  and the pin is LOW
    else                            ; or if LED is ON when LOW
        btfss  Port, Bit            ;  and the pin is HIGH
    endif                            ; then the LED is OFF
    goto      Label                  ;    so don't jump to the label
  endm                                     
;------------------------------- 
ifLEDisOFF  macro Port,Bit, Label
    if (USB_LEDPOLARITY == 1)        ; if LED is ON when HIGH
        btfss  Port, Bit            ;  and the pin is HIGH
    else                            ; or if LED is ON when LOW
        btfsc  Port, Bit            ;  and the pin is LOW
    endif                            ; then the LED is ON
    goto      Label                  ;    so don't jump to the label
  endm 
ENDASM

---

As you can see from macros, Darrel used HIGH and LOW commands from PBP to handle BANK, TRIS, and output register of port.

To turn TX LED:

Code:

---

;----[Send USB data]--------------------------------------------------------
DoUSBOut:
    ASM
        ifdef    USB_TXLED
            LEDON  USB_TXLED
        endif 
    ENDASM
....

---

He call LED macro from DoUSBOut subrutine...

Code:

---

DoUSBService:
    INTS_FROM = INTS_FROM | UIR
ASM
  ifdef USB_ServiceLED
    LEDON  USB_ServiceLED
  endif
ENDASM

---

etc...

Argh, I had looked for FLAG in the include.

And I just noticed I can't rename those as I wish either, ooops.

Robert

"DEFINEs in PBP are converted literally to Assembly Language #DEFINE directives." from the PBP manual.

The "DEFINE USB_RXrcv POTRD,2" in PBP is converted to "#DEFINE USB_RXrcv PORTD,2"
An Assembly "#Define" in this case is just a text substitution.
In the Assembly code, wherever "USB_RXrcv" is, it is substituted (replaced) with "PORTD,2"

Thank you, that's what I thought from Pedja's post.

Robert