HT46F46E/HT46F47E/HT46F48E/HT46F49E
tempreg1 db
tempreg2 db
?
?
; temporary register #1
; temporary register #2
:
:
mov
mov
a,06h
tblp,a
:
:
; initialise table pointer - note that this address
; is referenced
; to the last page or present page
tabrdl
tempreg1
; transfers value in table referenced by table pointer
; to tempregl
; data at prog. memory address ²706H² transferred to
; tempreg1 and TBLH
dec
tblp
; reduce value of table pointer by one
tabrdl
tempreg2
; transfers value in table referenced by table pointer
; to tempreg2
; data at prog.memory address ²705H² transferred to
; tempreg2 and TBLH
; in this example the data ²1AH² is transferred to
; tempreg1 and data ²0FH² to register tempreg2
; the value ²00H² will be transferred to the high byte
; register TBLH
:
:
org
Dc
700h
; sets initial address of last page (for HT46F47E)
00Ah, 00Bh, 00Ch, 00Dh, 00Eh, 00Fh, 01Ah, 01Bh
:
:
Because the TBLH register is a read-only register and
cannot be restored, care should be taken to ensure its
protection if both the main routine and Interrupt Service
Routine use table read instructions. If using the table
read instructions, the Interrupt Service Routines may
change the value of the TBLH and subsequently cause
errors if used again by the main routine. As a rule it is
recommended that simultaneous use of the table read
instructions should be avoided. However, in situations
where simultaneous use cannot be avoided, the inter-
rupts should be disabled prior to the execution of any
main routine table-read instructions. Note that all table
related instructions require two instruction cycles to
complete their operation.
ifications to their programs on the same device. As an ad-
ditional convenience, Holtek has provided a means of
programming the microcontroller in-circuit. This provides
manufacturers with the possibility of manufacturing their
circuit boards complete with a programmed or un-pro-
grammed Flash Type microcontroller, and then program-
ming or upgrading the program at a later stage. This
enables product manufacturers to easily keep their manu-
factured products supplied with the latest program re-
leases without removal and re-insertion of the device.
Pin Name
PA0
Function
Serial data input/output
Serial clock
PA4
RES
Device reset
In Circuit Programming
VDD
Power supply
The provision of Flash Program Memory gives the user
and designer the convenience of easy upgrades and mod-
VSS
Ground
Table Location Bits
Instruction
b11
TABRDC[m] PC11 PC10 PC9
TABRDL [m]
b10
b9
b8
PC8
1
b7
@7
@7
b6
@6
@6
b5
@5
@5
b4
@4
@4
b3
@3
@3
b2
@2
@2
b1
@1
@1
b0
@0
@0
1
1
1
Table Location
Note: PC11~PC8: Current Program Counter bits
@7~@0: Table Pointer TBLP bits
For the HT46F49E the Table address location is 12 bits, i.e. from b11~b0.
For the HT46F47E and HT46F48E, the Table address location is 11 bits, i.e. from b10~b0.
For the HT46F46E, the Table address location is 10 bits, i.e. from b9~b0.
Rev. 1.31
13
January 9, 2009
HOLTEK [ HOLTEK SEMICONDUCTOR INC ]
