Sample USB descriptor definition for USB-CDC with Cypress EZ-USB FX2/FX2LP + SDCC

dscr.a51

;;; -*- mode: asm; coding: utf-8 -*-
;;;
;;; USB descriptor definition for virtual COM port implementation
;;; with Cypress EZ-USB FX2 (CY7C68013) and FX2LP (CY7C68013A).
;;;
;;; NOTE:
;;; - Works with sdcc, but may need recent version due to use of
;;;   assembler macros.
;;; 

.module DEV_DSCR 

;; descriptor types
DSCR_DEVICE_TYPE=1
DSCR_CONFIG_TYPE=2
DSCR_STRING_TYPE=3
DSCR_INTERFACE_TYPE=4
DSCR_ENDPOINT_TYPE=5
DSCR_DEVQUAL_TYPE=6

;; for the repeating interfaces
DSCR_INTERFACE_LEN=9
DSCR_ENDPOINT_LEN=7

;; endpoint types
ENDPOINT_TYPE_CONTROL=0
ENDPOINT_TYPE_ISO=1
ENDPOINT_TYPE_BULK=2
ENDPOINT_TYPE_INT=3

;; ENDPOINT DIRECTION
EP_IN  = 0x80
EP_OUT = 0x00

;;
EP1 = 1
EP2 = 2
EP3 = 3
EP4 = 4
EP5 = 5
EP6 = 6
EP7 = 7
EP8 = 8

;; function descriptor
CS_INTERFACE = 0x24
CS_ENDPOINT = 0x25

;; Symbols used in setupdat.c
.globl _dev_dscr, _dev_qual_dscr, _highspd_dscr, _fullspd_dscr, _dev_strings, _dev_strings_end

;; Edit makefile to place this area in code memory (SUDPTRH:L requirement)
.area DSCR_AREA (CODE)

;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
;;; Device Descriptor
;;; 
;;; @see CDC120-20101103-track.pdf in http://www.usb.org/developers/docs/devclass_docs/CDC1.2_WMC1.1_012011.zip
;;; - 5.1.1  Device Descriptor
;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
_dev_dscr:
	.db dev_dscr_end - _dev_dscr	; descriptor size
	.db DSCR_DEVICE_TYPE		; descriptor device type
	.dw 0x0002			; USB version (0x02 0x00, LSB-first)

	.db 0x02	; device class = Communication Device Class (CDC)
	.db 0x00	; subclass = unused
	.db 0x00	; protocol = unused
	.db 64		; packet size (ep0)
	.dw 0xB404	; vendor  id
	.dw 0x4717	; product id
	.dw 0x0001	; version id (1.0 = 0x01 0x00, LSB-first)
	.db 1		; manufacturure string index
	.db 2		; product string index
	.db 3		; serial string index
	.db 1		; n configurations
dev_dscr_end:

;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
;;; Device Qualifier Descriptor
;;;
;;; A high-speed capable device that has different device information
;;; for full-speed and high-speed must have a Device Qualifier
;;; Descriptor (USB_DEVICE_QUALIFIER_DESCRIPTOR). For example, if
;;; the device is currently operating at full-speed, the Device
;;; Qualifier returns information about how it would operate at
;;; high-speed and vice-versa.
;;; 
;;; @see http://www.keil.com/pack/doc/mw/usb/html/_u_s_b__device__qualifier__descriptor.html
;;; 
;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
_dev_qual_dscr:
	.db dev_qualdscr_end - _dev_qual_dscr
	.db DSCR_DEVQUAL_TYPE
	.dw 0x0002		; USB version (0x02 0x00, LSB-first)
	.db 0x00		; device class = 0x00:use interface class
	.db 0x00		; device sub-class
	.db 0x00		; device sub-sub-class
	.db 64			; max packet
	.db 1			; n configs
	.db 0			; extra reserved byte
dev_qualdscr_end:

;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
;;; Configuration for High-Speed mode
;;; 
;;; [CDC]  5.1.2  Configuration Descriptor
;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
_highspd_dscr:
	.db highspd_dscr_end-_highspd_dscr	; descriptor length
	.db DSCR_CONFIG_TYPE			; descriptor type

	;; NOTE: can't use .dw because byte order is different
	.db (highspd_dscr_realend-_highspd_dscr) % 256 ; total length of config (LSB)
	.db (highspd_dscr_realend-_highspd_dscr) / 256 ; total length of config (MSB)

	.db 2		  ; n interfaces
	.db 1		  ; config number
	.db 4		  ; config string index
	.db 0x80	  ; attriubutes (see spec for bit description)
	.db 50		  ; max power = $val * 2[mA]
highspd_dscr_end:

.macro ifdesc
;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
;;; Interface #0.0 - Communications Class
;;; 
;;; @see CDC120-20101103-track.pdf
;;; - 4 Class-Specific Codes
;;; - 5.1.3  Interface Descriptor
;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;

	.db DSCR_INTERFACE_LEN
	.db DSCR_INTERFACE_TYPE
	.db 0			; interface index
	.db 0			; altsetting index
	.db 1			; n endpoints	
	.db 0x02    		; interface class = Communication Interface Class
	.db 0x02       		; interface sub-class = Abstract Control Model
	.db 0x01 		; interface protocol code class = AT Commands V.250
	.db 5			; interface descriptor string index

	;;
	;; 5.2.3  Functional Descriptors
	;;
	;; This is based on a sample functional descriptor described in
	;;
	;;   USB Class Definition for Communication Devices
	;;   - Table 18: Sample Communications Class Specific Interface Descriptor
	;;   - http://www.usb.org/developers/docs/devclass_docs/CDC1.2_WMC1.1_012011.zip
	;;     - CDC120-20101103-track.pdf
	;;

	;; Header Functional Descriptor
        .db 0x05   ; size
	.db CS_INTERFACE
	.db 0x00   ; subtype = Header FD
	.dw 0x1001 ; bcdCDC release number (0110h, LSB-first)

	;; Abstract Control Model Functional Descriptor
	;; @see PSTN120.pdf, Table 4: Abstract Control Management Functional Descriptor 
	.db 0x04   ; size
	.db CS_INTERFACE
	.db 0x02   ; subtype = ACM-FD
	.db 0x02   ; bmCapabilities

	;; Union Functional Descriptor
	.db 0x05   ; size
	.db CS_INTERFACE
	.db 0x06   ; subtype = Union FD
	.db 0      ; bControlInterface      (I/F# of Communication Class Interface)
	.db 1      ; bSubordinateInterface0 (I/F# of Data Class Interface)

     	;; Call Management Functional Descriptor
	;; @see PSTN120.pdf, Table 3: Call Management Functional Descriptor
	.db 0x05   ; size
	.db CS_INTERFACE
	.db 0x01   ; subtype = CM-FD
	.db 0x00   ; bmCapabilities
	.db 0x01   ; bDataInterface

	;; EP1
	.db DSCR_ENDPOINT_LEN
	.db DSCR_ENDPOINT_TYPE
	.db EP1 + EP_IN
	.db ENDPOINT_TYPE_INT
	.db 0x10		; max packet size (LSB)
	.db 0x00		; max packet size (MSB)
	.db 0x02		; polling interval

;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
;;; Interface #1.0 - Data Class Interface
;;; 
;;; [CDC] 4.5  Data Class Interface Codes
;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;

	.db DSCR_INTERFACE_LEN
	.db DSCR_INTERFACE_TYPE
	.db 1			; interface index
	.db 0			; altsetting index
	.db 2			; n endpoints	
	.db 0x0A		; interface class = CDC-Data
	.db 0x00		; interface sub-class = unused
	.db 0x00		; interface protocol code class = None
	.db 6			; interface descriptor string index

	;; EP1
	.db DSCR_ENDPOINT_LEN
	.db DSCR_ENDPOINT_TYPE
	.db EP1 + EP_OUT
	.db ENDPOINT_TYPE_BULK
	.db 0x40		; max packet size (LSB)
	.db 0x00		; max packet size (MSB)
	.db 0x00		; polling interval

	;; EP8
	.db DSCR_ENDPOINT_LEN
	.db DSCR_ENDPOINT_TYPE
	.db EP8 + EP_IN
	.db ENDPOINT_TYPE_BULK
	.db 0x00		; max packet size (LSB)
	.db 0x02		; max packet size (MSB)
	.db 0x00		; polling interval
.endm
	ifdesc
highspd_dscr_realend:

;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
;;; Configuration for Full-Speed mode
;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
	.even
_fullspd_dscr:
	.db fullspd_dscr_end - _fullspd_dscr      ; descriptor size
	.db DSCR_CONFIG_TYPE			  ; descriptor type

	;; can't use .dw because byte order is different
	.db (fullspd_dscr_realend - _fullspd_dscr) % 256 ; total length of config (LSB)
	.db (fullspd_dscr_realend - _fullspd_dscr) / 256 ; total length of config (MSB)

	.db 2		; n interfaces
	.db 1		; config number
	.db 4		; config string index
	.db 0x80	; attributes = bus powered, no wakeup
	.db 50		; max power = $val * 2[mA]
fullspd_dscr_end:
	;; use macro to insert same descriptor as high-speed
	;; 
	;; TODO:
	;; - Enhance macro, so it can use different EP packet size
	ifdesc
fullspd_dscr_realend:

;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
;;; String Tables
;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
	.even
_dev_strings:
.macro usbstring mystr
	.nchr len, mystr
	.db 2 + len * 2
	.db DSCR_STRING_TYPE
	.irpc c, mystr
	.strz ''c''
	.endm
.endm
	;; First entry is a language id, not a string data.
	;; @see http://www.usb.org/developers/docs/USB_LANGIDs.pdf
	.db 4
	.db DSCR_STRING_TYPE
	.db 0x09, 0x04		; 0x0409: U.S. English

	;; Actual string data.
	;; NOTE: In decsriptor, string index #0 means "No string to use"
str1:	usbstring ^!^/Mfg X/!
str2:	usbstring ^!^/Prd X/!
str3:	usbstring ^!^/Ser X/!
str4:	usbstring ^!^/Cfg1/!
str5:	usbstring ^!^/CommIF/!
str6:	usbstring ^!^/DataIF/!

	;; Last entry is a sentinel to mark END-OF-STRING-TABLE
	.dw 0x0000
_dev_strings_end:

Thanks for this.