M68HC11_03 Datasheet, PDF (251/268 Pages) Motorola, Inc – 8-channel, 8-bit analog-to-digital (A/D) converter

Freescale Semiconductor, Inc.
Application Note
95
****************************************************
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* PROGRAM - Utility subroutine to program EPROM.
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* Prior to calling PROGRAM set baud rate, turn on SCI
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* set X=2ms prog delay constant, and set Y=first
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* address to program. SP must point to RAM.
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* Bootloader leaves baud set, SCI enabled, X=4200
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* and Y pointing at EPROM start ($D000) so these
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* default values don't have to be changed typically.
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* Delay constant in X should be equivalent to 2 ms
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* at 2.1 MHz X=4200; at 1 MHz X=2000.
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* An external voltage source is required for EPROM
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* programming.
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* This routine uses 2 bytes of stack space
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* Routine does not return. Reset to exit.
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****************************************************
110 BF13
PRGROUT EQU *
111 BF13 3C
PSHX
Save program delay constant
112 BF14 CE1000
LDX #$1000
Point to internal registers
113 BF17
114
* Send $FF to indicate ready for program data
115
116 BF17 1F2E80FC
BRCLR SCSR,X $80 * Wait for TDRE
117 BF1B 86FF
LDAA #$FF
118 BF1D A72F
STAA SCDAT,X
119
120 BF1F
WAIT1 EQU *
121 BF1F 1F2E20FC
BRCLR SCSR,X $20 * Wait for RDRF
122 BF23 E62F
LDAB SCDAT,X
Get received byte
123 BF25 18E100
CMPB $0,Y
See if already programmed
124 BF28 271D
BEQ DONEIT
If so, skip prog cycle
125 BF2A 8620
LDAA #ELAT
Put EPROM in prog mode
126 BF2C A73B
STAA PPROG,X
127 BF2E 18E700
STAB 0,Y
Write the data
128 BF31 8621
LDAA #ELAT+EPGM
129 BF33 A73B
STAA PPROG,X
Turn on prog voltage
130 BF35 32
PULA
Pull delay constant
131 BF36 33
PULB
into D-reg
132 BF37 37
PSHB
But also keep delay
133 BF38 36
PSHA
keep delay on stack
134 BF39 E30E
ADDD TCNT,X
Delay const + present TCNT
135 BF3B ED16
STD TOC1,X
Schedule OC1 (2ms delay)
136 BF3D 8680
LDAA #OC1F
137 BF3F A723
STAA TFLG1,X
Clear any previous flag
138
139 BF41 1F2380FC
BRCLR TFLG1,X OC1F * Wait for delay to expire
140 BF45 6F3B
CLR PPROG,X
Turn off prog voltage
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*
142 BF47
DONEIT EQU *
143 BF47 1F2E80FC
BRCLR SCSR,X $80 * Wait for TDRE
144 BF4B 18A600
LDAA $0,Y
Read from EPROM and...
145 BF4E A72F
STAA SCDAT,X
Xmit for verify
146 BF50 1808
INY
Point at next location
147 BF52 20CB
BRA WAIT1
Back to top for next
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* Loops indefinitely as long as more data sent.
149
AN1060 — Rev. 1.0
MOTOROLA
251
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