Hitachi AP1 Data Book page 47

--------------------------------------------------------HMCS44C,HMCS44CL
• Program Counter (PC)
! - - - 6 4 words------!
1F OF 0 7 _ 3D 3E 3F (Hexa-decimal)
ftJi
0
ri
1
2
Program Area
30
ri 31
1 - - 6 4 words-----l
page
page
page
(
page
page
Timer/counter Interrupt Address (0 page 3F address)
Input Interrupt Address(1 page 3F address)
Reset Address (31 page 3F address)
1 F OF 07 _ 3D 3E 3F (Hexa-decimal)
Pattern Area
Pattern Area
61 page
62 page
Figure 1 ROM Address Space
The program counter is used for addressing of ROM. It con-
sists of the page part and the address part as shown in Figure 2.
Once a certain value is loaded into a page part, the content is
unchanged until other value is loaded by the program. The setta-
ble value of a page part is any number between 0 to 31.
Page Part
, - - - - Address Part - - -......
PCe
Figure 2 Configuration of Program Counter
The address part is a 6-bit polynomial counter and counts up
for each instruction cycle time_ The sequence in the decimal and
hexa-decimal system is shown in Table 1. This sequence is cir-
culating and has neither the starting nor ending point. It doesn't
generate an overflow carry. Consequently, the program on a
same page is executed in order unless the value of the page part
is changed.
Table 1 Program Counter Address Part Sequence
Decimal
Hexadecimal Decimal Hexadecimal Decimal Hexadecimal
63 3F 5 05 9 09
62
3E
11
OB 19 13
61 30 23 17 38 26
59 3B 46 2E 12 OC
55 37 28 1C 25 19
47 2F
56 38 50 32
30 1E 49 31 37
25
60 3C 35 23 10 OA
57
39 6 06 21 15
51
33 13 00 42 2A
39 27 27 1B
20 14
14 OE 54
36
40
28
29 10 45 20 16 10
58 3A
26 1A 32 20
53 35 52
34 0 00
43 2B 41 29 1 01
22 16 18 12 3 03
44
2C 36 24 7 07
24 18 8
08
15 OF
48 30 17 11 31 1F
33 21 34 22
2 02 4 04
45