Motorola DSP56301 User Manual

Page 301

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DSP56301 User’s Manual

A

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; HA[10] <- SBHE_ ; selects HI32 (base address 10011111)

; HA[9] <- SA[0] ; selects HI32 (base address 10011111)

; HA[8:3] <- SA[9:4] ; selects HI32 (base address 10011111)

; HA[2:0] <- SA[3:1] ; selects HTXR registers

; HD[15:0] - SD[15:0] ; Data bus

; HD[23:16] - Not connected ; High Data Bus - Should be pulled up or down

; HDBEN_ -> OE_ ; Output enable of transcievers

; HDBDR -> DIR ; Direction of transcievers

; HSAK_ -> IO16_ ; 16 bit data word

; HBS_ <- Vcc ; Bus Strobe disabled

; HAEN <- AEN ; DMA cycle enable

; HTA -> CHRDY ; Channel ready

; HWR_ <- IOWC_ ; IO/DMA write strobe

; HRD_ <- IORC_ ; IO/DMA read strobe

; HRST <- inverted RSTDRV ; invert ISA reset

;

;

;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;

; If MD:MC:MB:MA=x110, then it loads the program RAM from the Host

; Interface programmed to operate in the Universal Bus (UB) mode, in

; double-strobe pin configuration.

;

; The HI32 bootstrap code expects first to receive 3 bytes specifying the

; number of program words, then 3 bytes specifying the address to

; start loading the program words and then 3 bytes for each program word

; to be loaded. The number of words, the starting address and the program

; words are received least significant byte first followed by the mid and

; then by the most significant byte.

;

; The program words will be condensed into 24-bit words and stored in

; contiguous PRAM memory locations starting at the specified starting

; address. After reading the program words, program execution starts

; from the same address where loading started.

;

; The Host Interface bootstrap load program may be stopped by setting the

; Host Flag 0 (HF0) in HCTR register. This will start execution of the

; loaded program from the specified starting address.

;

; The user must externally decode the port address with active low logic and

; connect the select line to HAEN; all the address lines shall be pulled down

; except for HA3, HA2 and HA1 that select the HOST Interface registers.

;

; When booting through the Host Interface it is recommended that the Host

; boot program verify that the Host Interface is operational by

; reading the status register (HSTR) and confirm that TRDY=1.

;

; When booting through the Host Interface, it is recommended that the

; HOST Processor’s boot program verify that the Host Interface is

; ready by reading the status register (HSTR) and confirm that TRDY=1

; or HTRQ=1.

;

;

;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;

; If MD:MC:MB:MA=x111, then it loads the program RAM from the Host

; Interface programmed to operate in the Universal Bus (UB) mode, in

; single-strobe pin configuration.

;

; Other than the single-strobe pin configuration, this mode is identical to

; the double-strobe pin configuration UB mode (MD:MC:MB:MA=x110).

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