Accessing HEF

[mpgmike]

I'm working with a PIC16F1619 which doesn't have an "EEPROM", but instead uses High Endurance Flash (HEF). I have spent considerable time with the data sheet as well as AN1673, a MicroChip Application Note specifically on the HEF & PIC16F1XXX processors. It would be grand if I could save one single variable to the HEF that can be retrieved at start-up. Here's what I have:

Cyls        var     byte
Start:
GOSUB Write_HEF
GOSUB Read_HEF

Write_HEF:
ASM
    BANKSEL PMADRH
    MOVF    0Fh,W
    MOVWF   PMADRH                          ;PMADRH = $0F, 1st HEF Address is 0F80h
    MOVF    80h,W
    MOVWF   PMADRL                          ;PMADRL = $80
    BCF     PMCON1,CFGS
    BSF     PMCON1,WREN
    BSF     PMCON1,LWLO
    MOVIW   _Cyls
    MOVWF   PMDATL

ENDASM
    GOSUB UnlockHef
@   BCF     PMCON1,LWLO
    GOSUB UnlockHef
@   BCF     PMCON1,WREN   
RETURN

Read_HEF:
ASM
    BANKSEL PMADRL                          ; Select Bank for PMCON registers 
    MOVLW   0x80h                           ; 
    MOVWF   PMADRL                          ; Store LSB of address 
    MOVLW   0x0F                            ;
    MOVWF   PMADRH                          ; Store MSB of address
    BCF     PMCON1,CFGS                     ; Do not select Configuration Space
    BSF     PMCON1,RD                       ; Initiate read
    NOP
    NOP
    MOVF    PMDATL,W                        ; Get LSB of word
    MOVWF   _Cyls                           ; Store in user location 
    MOVF    PMDATH,W                        ; Get MSB of word
    MOVWF   _b0                             ; Store in user location
ENDASM
RETURN

UnlockHEF:
asm
    BANKSEL PMCON2
    MOVLW   55h
    MOVWF   PMCON2
    MOVLW   AAh
    MOVWF   PMCON2
    BSF     PMCON1,WR                       ; set WR bit
    NOP
    NOP
endasm
RETURN

What am I missing?

[richard]

This is working but to be really useful you need to implement a block structure of say 32 14bit words that you can erase and rewrite as required
individual words can be read but the whole block must be erased and rewritten to modify an individual word.

strangely the pbp [ver 3.010.4] MOVE macros fail to load the PMDAT latches correctly so its done longhand , I have not investigated why

'****************************************************************
'*  Name    : hef_Test.PBP                                   *
'*  Author  :                                                   *
'*  Notice  :                                                   *
'*          :                                                   *
'*  Date    :                                                   *
'*  Version :                                    *
'*  Notes   : PIC16F1619                                        *
'*          : hef TEST                                          *
'****************************************************************







#CONFIG
    __config _CONFIG1,  _FOSC_INTOSC & _PWRTE_OFF & _MCLRE_ON & _CP_OFF & _BOREN_ON & _CLKOUTEN_OFF & _IESO_OFF & _FCMEN_OFF
    __config _CONFIG2,  _WRT_OFF & _PPS1WAY_OFF & _ZCD_OFF & _PLLEN_OFF & _STVREN_ON & _BORV_HI & _LVP_ON
    __config _CONFIG3,  _WDTCPS_WDTCPS6 & _WDTE_OFF & _WDTCWS_WDTCWS100 & _WDTCCS_LFINTOSC
#ENDCONFIG

 define      OSC             32

; --- *** Oscillator  *** ---------------------------------------------------
OSCCON = %11110000           ;8 MHz, 4X PLL Enabled, 32 MHz
TRISA  = %11011011
TRISC  = 255
ANSELA = 0
ANSELC = 0



LED    VAR  PORTA.5  ' Assign name "LED" to  

'LCD defines begin here  
    DEFINE LCD_BITS 4  'defines the number of data interface lines (4 or 8)
    DEFINE LCD_DREG PORTB 'defines the port where data lines are connected to
    DEFINE LCD_DBIT 4  'defines the position of data lines for 4-bit interface (0 or 4)
    DEFINE LCD_RSREG PORTC 'defines the port where RS line is connected to
    DEFINE LCD_RSBIT 2  'defines the pin where RS line is connected to
    DEFINE LCD_EREG PORTC  'defines the port where E line is connected to
    DEFINE LCD_EBIT 1  'defines the pin where E line is connected
    DEFINE LCD_RWREG PORTC ' LCD read/write port
    DEFINE LCD_RWBIT 0 ' LCD read/write pin bit
    DEFINE LCD_COMMANDUS 1500  'defines the delay after LCDOUT statement
    DEFINE LCD_DATAUS 50   'delay in micro seconds
'END of LCD DEFINES

Cyls        var     WORD
RESULT      var     WORD


Cyls = 12340
Pause 500       ' LCD initialize time
lcdout $FE,1,"ready "
Pause 2000

lcdout $FE,1,"WRITING " ,#Cyls

GOSUB Write_HEF

READCODE $1F80,  RESULT

lcdout $FE,$C0,"read " ,#RESULT





STOP

Write_HEF:
ASM
    BANKSEL PMADRH
    MOVLW    1Fh
    MOVWF   PMADRH                        
    MOVLW    80h
    MOVWF   PMADRL                        
    BCF     PMCON1,CFGS
    BSF     PMCON1,WREN
    BSF     PMCON1,LWLO
[COLOR=#008000]   ;MOVE?BA  _Cyls            ; BYTE MACRO'S FAIL HERE
    ;MOVE?AB  PMDATL           ;      "
    ;MOVE?BA  _Cyls+1          ;      "
    ;MOVE?AB  PMDATH           ;      "
    ;MOVE?BB   _Cyls,  PMDATL  ;    AND THESE TOO FAIL
    ;MOVE?BB   _Cyls+1,PMDATH  ;      "
    ;MOVE?WW   _Cyls,  PMDATL  ; WORD MACRO FAILS HERE[/COLOR]
    BANKSEL    _Cyls
    movf _Cyls,w
    BANKSEL  PMDATL
    movwf PMDATL
    BANKSEL _Cyls
    movf _Cyls+1,w
    BANKSEL PMDATH
    MOVWF    PMDATH
    ;L?CALL UnlockHef    ; unnecessary here
    BANKSEL PMCON1
    BCF     PMCON1,LWLO
    L?CALL UnlockHef
    BANKSEL PMCON1
    BCF     PMCON1,WREN
    RST?RP
    RETURN
UnlockHef
    BANKSEL PMCON2
    MOVLW   55h
    MOVWF   PMCON2
    MOVLW   0AAh
    MOVWF   PMCON2
    BSF     PMCON1,WR                    
    NOP
    NOP
    RETURN
endasm

[richard]

data sheet is a bit of a mystery

High-Endurance Flash Data Memory (HEF):

- 128 B of nonvolatile data storage

- 100K erase/write cycles

later on is says 1024 bytes for 16f1619

but start addr is still 1f80

[FONT=Arial][SIZE=8px][FONT=Arial][SIZE=8px]PIC16(L)F1615/9 8,192 1FFFh 1F80h-1FFFh[/SIZE][/FONT][/SIZE][/FONT]

[FONT=Arial][SIZE=8px][FONT=Arial][SIZE=8px][B]Note 1: [/B][/SIZE][/FONT][/SIZE][/FONT][FONT=Arial][SIZE=8px][FONT=Arial][SIZE=8px]High-endurance Flash applies to low byte of each address in the range.[/SIZE][/FONT][/SIZE][/FONT]

how can you only write to the low byte ?

[richard]

a version that saves 1 to 32 vars to hef

[mpgmike]

Thank you very much.