MC68HC11KW1 Datasheet, PDF (71/238 Pages) Motorola, Inc – High-density complementary metal oxide semiconductor HCMOS) microcontroller unit

In another example the user wishes to allocate two windows. The first window is organized as in
the previous example, 8 banks of 8K bytes each. The second window is organized as 16 banks of
16K bytes each. The logical addresses in window 2 are determined by CPU address lines
ADDR[13:0]. Note that XA13 replaces ADDR13 for each memory device in this example since
ADDR13 is driven on XA13. Expansion address lines XA[17:14] add another 16 (24) times the
number of address locations provided by ADDR[13:0] (256K bytes total address space). ADDR13
may also be used instead of XA13 for the 6226 memory devices if the designer chooses. This is
illustrated in Figure 4-3 and Figure 4-6. Figure 4-3 shows a memory map and Figure 4-6 shows a
schematic for one 8K byte window with 8 banks of external memory, and one 16K byte window
with 16 banks of external memory.
4
$0000 _{Registers, RAM}
and EEPROM
Window 1
$00000 $02000 $04000 $06000 $08000 $0A000 $0C000 $0E000
$4000
$6000
Chip select 1
Bank 0 Bank 1 Bank 2 Bank 3 Bank 4 Bank 5 Bank 6 Bank 7
XA[15:13] XA[15:13] XA[15:13] XA[15:13] XA[15:13] XA[15:13] XA[15:13] XA[15:13]
= 0:0:0 = 0:0:1 = 0:1:0 = 0:1:1 = 1:0:0 = 1:0:1 = 1:1:0 = 1:1:1
$01FFF $03FFF $05FFF $07FFF $09FFF $0BFFF $0DFFF $0FFFF
Window 2
$00000 $04000 $08000 $0C000 $10000
$3C000
$8000
$C000
Chip select 2
Bank 0 Bank 1 Bank 2 Bank 3 Bank 4
XA[15:13] XA[15:13] XA[15:13] XA[15:13] XA[15:13]
= 0:0:0:0 = 0:0:0:1 = 0:0:1:0 = 0:0:1:1 = 0:1:0:0
Bank15
XA[15:13]
= 1:1:1:1
$FFC0
$FFFF
Vectors
$03FFF $07FFF $0BFFF $0FFFF $13FFF
$3FFFF
PGAR = $1F
MMWBR = $84
MMSIZ = $42
XA[17:13]
window 1 @ $4000,
window 2 @ $8000
window 1 = 8K bytes,
window 2 = 16K bytes
CSCTL = $00
GPCS1A = $00
GPSC1C = $06
GPCS2A = $00
GPCS2C = $08
no I/O or program chip selects
general purpose chip select 1 from $00000
64K byte range (8 x 8K)
general purpose chip select 2 from $00000
256K byte range (16 x 16K)
Figure 4-5 Memory map example of memory expansion
MC68HC11KW1
OPERATING MODES AND ON-CHIP MEMORY
4-27