Holtek HT48R30A-1 User Manual

With the exception of the HT48RU80/HT48CU80 devices, the following diagram illustrates the ad
-
dressing/data flow of the look-up table:
Table Program Example
The following example shows how the table pointer and table data is defined and retrieved from
the HT48R10A-1/HT48C10-1 I/O microcontroller. This example uses raw table data located in the
last page which is stored there using the ORG statement. The value at this ORG statement is
²300H² which refers to the start address of the last page within the 1K Program Memory of the
HT48R10A-1/HT48C10-1 microcontroller. The table pointer is setup here to have an initial value
of ²06H². This will ensure that the first data read from the data table will be at the Program Memory
address ²306H² or 6 locations after the start of the last page. Note that the value for the table
pointer is referenced to the first address of the present page if the ²TABRDC [m]² instruction is be
-
ing used. The high byte of the table data which in this case is equal to zero will be transferred to the
TBLH register automatically when the ²TABRDL [m]² instruction is executed.
tempreg1 db ? ; temporary register #1
tempreg2 db ? ; temporary register #2
:
:
mov a,06h ; initialize table pointer - note that this address is
; referenced
mov tblp,a ; to the last page or present page
:
:
tabrdl tempreg1 ; transfers value in table referenced by table pointer
; to tempregl
; data at prog. memory address 306H 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 305H 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 300h ; sets initial address of last page (for HT48R10A-1)
dc 00Ah, 00Bh, 00Ch, 00Dh, 00Eh, 00Fh, 01Ah, 01Bh
:
:
Chapter 1 Hardware Structure
25
P r o g r a m
M e m o r y
P r o g r a m C o u n t e r
H i g h B y t e
T B L P
T B L H S p e c i f i e d b y [ m ]
H i g h b y t e o f t a b l e c o n t e n t s
L o w b y t e o f t a b l e c o n t e n t s

Holtek HT48R30A-1 Specifications

General

Brand	Holtek
Model	HT48R30A-1
Category	Microcontrollers
Language	English