Segment 0

Segment 1

Line 0

Line 1

Line 2

Line 3

Line 4

Line 5

Line 6

Line 7

Line 0

Line 1

Line 2

Line 3

Line 4

Line 5

Line 6

Line 7

Mem Addr

00

01

02

03

04

05

06

07

08

09

0a

0b

0c

0d

0e

0f

10

11

12

13

14

15

16

17

18

19

1a

1b

1c

1d

1e

1f

Data

37

01

f4

1b

17

b0

22

01

05

0b

e2

dc

b8

35

92

29

f0

3f

cb

45

f1

3d

ce

47

f2

3d

7e

79

f3

3c

b4

99

	Segment 2																Segment 3
	Line 0		Line 1		Line 2		Line 3		Line 4		Line 5		Line 6		Line 7		Line 0		Line 1		Line 2		Line 3		Line 4		Line 5		Line 6		Line 7
Mem Addr	20	21	22	23	24	25	26	27	28	29	2a	2b	2c	2d	2e	2f	30	31	32	33	34	35	36	37	38	39	3a	3b	3c	3d	3e	3f
Data	00	01	07	1f	02	03	09	1e	04	05	11	1d	06	07	31	dd

The data cache table is 2 cells by 8 lines, each cell holds 1 byte of data.
Only data is cached in this example (not instuctions).

For this example, assume a write to a non-cached memory location will first cause the memory to be loaded into the cache, i.e, first time STA $22 is executed, Line 0 of Segment 2 is moved into the cache before the Accumulator is stored.

Empty cache	LDA $00 - Miss - 37	ADC $0A - Miss - e2	SBC $22 - Miss - 07
	00h = 0000 000 0b tag = 0, line = 0, byte = 0	0Ah = 0000 101 0b tag = 0, line = 5, byte = 0	22h = 0010 001 0b tag = 2, line = 1, byte = 0
Line Tag  Data  07       06       05       04       03       02       01       00       Shaded not part of cache	Line Tag  Data  07       06       05       04       03       02       01       00 0 37 01 Grey not part of cache	Line Tag  Data  07       06       05 0 e2 dc 04       03       02       01       00 0 37 01 Grey not part of cache	Line Tag  Data  07       06       05 0 e2 dc 04       03       02       01 2 07 1f 00 0 37 01 Grey not part of cache

ADC $01 - Hit - 01	SBC $0B - Hit - dc	ADC $23 - Hit - 1f
01h = 0000 000 1b tag = 0, line = 0, byte = 1	0Bh = 0000 101 1b tag = 0, line = 5, byte = 1	23h = 0010 001 1b tag = 2, line = 1, byte = 1
Line Tag  Data  07       06       05 0 e2 dc 04       03       02       01 2 07 1f 00 0 37 01 Grey not part of cache	Line Tag  Data  07       06       05 0 e2 dc 04       03       02       01 2 07 1f 00 0 37 01 Grey not part of cache	Line Tag  Data  07       06       05 0 e2 dc 04       03       02       01 2 07 1f 00 0 37 01 Grey not part of cache

SBC $02 - Miss - f4	ADC $0C - Miss - b8	SBC $02 - Hit - f4
02h = 0000 001 0b tag = 0, line = 1, byte = 0	0Ch = 0000 110 0b tag = 0, line = 6, byte = 0	24h = 0010 010 0b tag = 2, line = 2, byte = 0
Line Tag  Data  07       06       05 0 e2 dc 04       03       02       01 0 f4 1b 00 0 37 01 Grey not part of cache	Line Tag  Data  07       06 0 b8 35 05 0 e2 dc 04       03       02       01 0 f4 1b 00 0 37 01 Grey not part of cache	Line Tag  Data  07       06 0 b8 35 05 0 e2 dc 04       03       02       01 0 f4 1b 00 0 37 01 Grey not part of cache

ADC $03 - Hit - 1b	SBC $0D - Hit - 35	ADC $25 - Miss - 03
03h = 0000 001 1b tag = 0, line = 1, byte = 1	0Dh = 0000 110 1b tag = 0, line = 6, byte = 1	25h = 0010 010 1b tag = 2, line = 2, byte = 1
Line Tag  Data  07       06 0 b8 35 05 0 e2 dc 04       03       02       01 0 f4 1b 00 0 37 01 Grey not part of cache	Line Tag  Data  07       06 0 b8 35 05 0 e2 dc 04       03       02       01 0 f4 1b 00 0 37 01 Grey not part of cache	Line Tag  Data  07       06 0 b8 35 05 0 e2 dc 04       03       02 2 02 03 01 0 f4 1b 00 0 37 01 Grey not part of cache