descript.asm

This firmware translates a PS/2 mouse to a USB mouse. The translator firmware is entirely interrup

;                            Software License Agreement
;
; The software supplied herewith by Microchip Technology Incorporated (the "Company")
; for its PICmicro(r) Microcontroller is intended and supplied to you, the Company's
; customer, for use solely and exclusively on Microchip PICmicro Microcontroller
; products.
;
; The software is owned by the Company and/or its supplier, and is protected under
; applicable copyright laws. All rights are reserved. Any use in violation of the
; foregoing restrictions may subject the user to criminal sanctions under applicable
; laws, as well as to civil liability for the breach of the terms and conditions of
; this license.
;
; THIS SOFTWARE IS PROVIDED IN AN "AS IS" CONDITION. NO WARRANTIES, WHETHER EXPRESS,
; IMPLIED OR STATUTORY, INCLUDING, BUT NOT LIMITED TO, IMPLIED WARRANTIES OF
; MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE APPLY TO THIS SOFTWARE. THE
; COMPANY SHALL NOT, IN ANY CIRCUMSTANCES, BE LIABLE FOR SPECIAL, INCIDENTAL OR
; CONSEQUENTIAL DAMAGES, FOR ANY REASON WHATSOEVER.
;
; ###############################################################################
;   filename:           DESCRIPT.ASM
;
; This file contains a set of descriptors for a standard mouse.  
;
; ###############################################################################
;
;   Author:             Dan Butler and Reston Condit
;   Company:            Microchip Technology Inc
;
;   Revision:           1.21
;   Date:               08 August 2001
;   Assembled using     MPASM 2.61
;   Revision History:
;   23 August 2000      DZB Changed descriptor pointers to 16 bits.
;   24 August 2000      DZB Moved EP1 & 2 configuration from USBReset
;                           to Set_Configuration to implement requirement in
;                           USB V1.1 spec paragraph 5.3.1.2
;   28 August 2000      DZB Force data toggle on OUT packets in PutUSB
;   20 March 2001       DZB Reduced use of common RAM
;   20 March 2001       DZB Put and Get use their own temp variable (GPtemp) to
;                           avoid collisions with the ISR's use of temp.
;   29 March 2001       DZB Fixed saving of bank bits in GetUSB
;   02 May 2001         DZB Implemented SHOW_ENUM_STATUS to show enumeration
;                           status on the PORTB LEDs: 0- Powered, 1- Default,
;                           2- addressed, 3- configured, 4- sleep, 
;                           5- EP0 Activity, 6- EP1 Activity, 7- EP2 Activity
;   03 August 2001      RAC Made distinct GetEP and PutEP macros for endpoints 1 
;                           and 2.  These functions are GetEP1, GetEP2, PutEP1, and 
;                           PutEP2.  Instances of the these macros are created in
;                           usb_ch9.asm.
;   08 August 2001      RAC Corrected various banking and paging issues.
;   15 August           RAC Added Report_desc_index function in descript.asm.
;                           This function allows more than one report descriptor
;                           to be used.  
;
;################################################################################
;
;   include files:
;       P16C765.inc     Rev 1.00
;       usb_defs.inc    Rev 1.00
;
;################################################################################
#include <p16C765.inc>
#include "usb_defs.inc"

USBBANK code
    global  Config_desc_index
    global  Report_desc_index
    global  Descriptions
    global  string_index
    global  DeviceDescriptor
    global  ReportDescriptor
    global  ReportDescriptorLen
    global  String0
    global  String0_end
    global  StringDescriptions
    global  HID_Descriptor

    extern  EP0_start
    extern  temp    ; temp var used in get config index
    extern  temp2   ; another temp, in bank2 

; ******************************************************************
; Given a configuration descriptor index, returns the beginning address
; of the descriptor within the descriptions table
; ******************************************************************
Config_desc_index
    movwf   temp
    movlw   HIGH CDI_start
    movwf   PCLATH
    movlw   low  CDI_start
    addwf   temp,w
    btfsc   STATUS,C
    incf    PCLATH,f
    movwf   PCL
CDI_start           ; this table calculates the offsets for each configuration
    retlw   low  Config1       ; descriptor from the beginning
    retlw   high Config1       ; of the table, effectively
    ; more configurations can be added here
    ; retlw   low Config2
    ; retlw   high Config2
    ; etc....

; ******************************************************************
; Given a report descriptor index, returns the beginning address
; of the descriptor within the descriptions table
; ******************************************************************
Report_desc_index
    movwf   temp
    movlw   HIGH RDI_start
    movwf   PCLATH
    movlw   low  RDI_start
    addwf   temp,w
    btfsc   STATUS,C
    incf    PCLATH,f
    movwf   PCL
RDI_start       ; this table calculates the offsets for each report
    retlw   low  ReportDescriptorLen  ; descriptor from the beginning
    retlw   high ReportDescriptorLen  ; of the table, effectively
    ; more reports can be added here
    ; retlw   low  ReportDescriptorLen2
    ; retlw   high ReportDescriptorLen2
    ; etc....

; ******************************************************************
; This table is polled by the host immediately after USB Reset has been released.
; This table defines the maximum packet size EP0 can take.
; See section 9.6.1 of the Rev 1.0 USB specification.
; These fields are application DEPENDENT. Modify these to meet
; your specifications.
; the offset is passed in P0 and P1 (P0 is low order byte).
; ******************************************************************
Descriptions
    banksel EP0_start
    movf    EP0_start+1,w
    movwf   PCLATH
    movf    EP0_start,w
    movwf   PCL

DeviceDescriptor
StartDevDescr
    retlw   0x12    ; bLength    Length of this descriptor
    retlw   0x01    ; bDescType This is a DEVICE descriptor
    retlw   0x00    ; bcdUSB    USB revision 1.10 (low byte)
    retlw   0x01    ; high byte
    retlw   0x00    ; bDeviceClass    zero means each interface operates independently
    retlw   0x00    ; bDeviceSubClass
    retlw   0x00    ; bDeviceProtocol
    retlw   0x08    ; bMaxPacketSize0 - inited in UsbInit()
    retlw   0xD8    ; idVendor - 0x04D8 is Microchip Vendor ID
    retlw   0x04    ; high order byte
    retlw   0x01    ; idProduct
    retlw   0x00
    retlw   0x41    ; bcdDevice
    retlw   0x04
    retlw   0x01    ; iManufacturer
    retlw   0x02    ; iProduct
    retlw   0x00    ; iSerialNumber - 3
    retlw   NUM_CONFIGURATIONS    ; bNumConfigurations

; ******************************************************************
; This table is retrieved by the host after the address has been set.
; This table defines the configurations available for the device.
; See section 9.6.2 of the Rev 1.0 USB specification (page 184).
; These fields are application DEPENDENT. 
; Modify these to meet your specifications.
; ******************************************************************
Config1
    retlw   0x09    ; bLength    Length of this descriptor
    retlw   0x02    ; bDescType    2=CONFIGURATION
    retlw   EndConfig1 - Config1
    retlw   0x00
    retlw   0x01    ; bNumInterfaces    Number of interfaces
    retlw   0x01    ; bConfigValue    Configuration Value
    retlw   0x04    ; iConfig    String Index for this config = #01
    retlw   0xA0    ; bmAttributes    attributes - bus powered
    retlw   0x32    ; MaxPower    self-powered draws 0 mA from the bus.
Interface1
    retlw   0x09    ; length of descriptor
    retlw   INTERFACE
    retlw   0x00    ; number of interface, 0 based array
    retlw   0x00    ; alternate setting
    retlw   0x01    ; number of endpoints used in this interface
    retlw   0x03    ; interface class - assigned by the USB
    retlw   0x01    ; boot device
    retlw   0x02    ; interface protocol - mouse
    retlw   0x05    ; index to string descriptor that describes this interface
HID_Descriptor
    retlw   0x09    ; descriptor size (9 bytes)
    retlw   0x21    ; descriptor type (HID)
    retlw   0x00
    retlw   0x01    ; HID class release number (1.00)
    retlw   0x00    ; Localized country code (none)
    retlw   0x01    ; # of HID class descriptor to follow (1)
    retlw   0x22    ; Report descriptor type (HID)
    retlw   (end_ReportDescriptor - ReportDescriptor)
    retlw   0x00
Endpoint1
    retlw   0x07    ; length of descriptor
    retlw   ENDPOINT
    retlw   0x81    ; EP1, In
    retlw   0x03    ; Interrupt
    retlw   0x04    ; max packet size (4 bytes) low order byte
    retlw   0x00    ; max packet size (4 bytes) high order byte
    retlw   0x0A    ; polling interval (10ms)
EndConfig1

ReportDescriptorLen
    retlw   low     (end_ReportDescriptor-ReportDescriptor)

ReportDescriptor
    retlw   0x05
    retlw   0x01    ; usage page (generic desktop)
    retlw   0x09
    retlw   0x02    ; usage (mouse)
    retlw   0xA1
    retlw   0x01    ; collection (application)
    retlw   0x09
    retlw   0x01    ;   usage (pointer)
    retlw   0xA1
    retlw   0x00    ;   collection (linked)
    retlw   0x05
    retlw   0x09    ;     usage page (buttons)
    retlw   0x19
    retlw   0x01    ;     usage minimum (1)
    retlw   0x29
    retlw   0x03    ;     usage maximum (3)
    retlw   0x15
    retlw   0x00    ;     logical minimum (0)
    retlw   0x25
    retlw   0x01    ;     logical maximum (1)
    retlw   0x95
    retlw   0x03    ;     report count (3)
    retlw   0x75
    retlw   0x01    ;     report size (1)
    retlw   0x81
    retlw   0x02    ;     input (3 button bits)
    retlw   0x95
    retlw   0x01    ;     report count (1)
    retlw   0x75
    retlw   0x05    ;     report size (5)
    retlw   0x81
    retlw   0x01    ;     input (constant 5 bit padding)
    retlw   0x05
    retlw   0x01    ;     usage page (generic desktop)
    retlw   0x09
    retlw   0x30    ;     usage (X)
    retlw   0x09
    retlw   0x31    ;     usage (Y)
    retlw   0x15
    retlw   0x81    ;     logical minimum (-127)
    retlw   0x25
    retlw   0x7F    ;     logical maximum (127)
    retlw   0x75
    retlw   0x08    ;     report size (8)
    retlw   0x95
    retlw   0x03    ;     report count (2)
    retlw   0x81
    retlw   0x06    ;     input (2 position bytes X & Y)
    retlw   0xC0    ;   end collection
    retlw   0xC0    ; end collection
end_ReportDescriptor

StringDescriptions
    banksel EP0_start
    movf    EP0_start+1,w
    movwf   PCLATH
    movf    EP0_start,w
    movwf   PCL

; ******************************************************************
; Given a configuration descriptor index, returns the beginning address
; of the descriptor within the descriptions table
; ******************************************************************
string_index        ; langid in W reg, string offset in EP0_start
    movwf   temp
    bcf     STATUS,C
    rlf     temp, f
    pagesel langid_index
    call    langid_index
    movwf   temp2
    incf    temp, f
    pagesel langid_index
    call    langid_index
    movwf   temp