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Rev. 1.40
24
March 29, 2019
Rev. 1.40
25
March 29, 2019
HT45F23A/HT45F24A
TinyPower
TM
Flash MCU with OPA & Comparators
HT45F23A/HT45F24A
TinyPower
TM
Flash MCU with OPA & Comparators
Table Read Program Example
tempreg1 db ? ; temporary register #1
tempreg2 db ? ; temporary register #2
:
:
mov a,06h ; initialise table pointer - note that this address is referenced
mov tblp,a ; to the last page or present page
mov a, 0Fh ; initialise high table pointer
mov tbhp, a
:
:
tabrdl tempreg1 ; transfers value in table referenced by table pointer to tempregl
; data at prog. memory address “0F06H” 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 “0F05H” transferred to tempreg2 and TBLH
; in this example the data “1AH” is transferred to tempreg1 and data “0FH”
; to register tempreg2 the value “00H” will be transferred to the high
;
byte
register
TBLH
:
:
org F00h ; sets initial address of last page
dc 00Ah, 00Bh, 00Ch, 00Dh, 00Eh, 00Fh, 01Ah, 01Bh
:
:
In Circuit Programming
The provision of Flash type Program Memory provides the user with a means of convenient and easy
upgrades and modifications to their programs on the same devices. As an additional convenience,
Holtek has provided a means of programming the microcontroller in-circuit using a 5-pin interface.
This provides manufacturers with the possibility of manufacturing their circuit boards complete with
a programmed or un-programmed microcontroller, and then programming or upgrading the program
at a later stage. This enables product manufacturers to easily keep their manufactured products
supplied with the latest program releases without removal and re-insertion of the devices.
Programming Pins
Function
DATA
Serial Data Input/Output
CLK
Serial Clock
RES
Device Reset
VDD
Power Supply
VSS
Ground
The Program Memory can be programmed serially in-circuit using this 5-wire interface. Data
is downloaded and uploaded serially on a single pin with an additional line for the clock. Two
additional lines are required for the power supply and one line for the reset. The technical details
regarding the in-circuit programming of the devices are beyond the scope of this document and will
be supplied in supplementary literature.
During the programming process the RES pin will be held low by the programmer disabling the
normal operation of the microcontroller and taking control of the PA0 and PA2 I/O pins for data
and clock programming purposes. The user must there take care to ensure that no other outputs are
connected to these two pins.