MC68HC11KW1 Datasheet, PDF (78/238 Pages) Motorola, Inc – High-density complementary metal oxide semiconductor HCMOS) microcontroller unit

4.5.4 CSCTL — Chip select control register
Chip select control (CSCTL)
Address bit 7
bit 6
bit 5
bit 4
bit 3
bit 2
bit 1
bit 0
State
on reset
$005B IOEN IOPL IOCSA IOSZ GCSPR PCSEN PCSZA PCSZB 0000 0100
IOEN — I/O chip select enable
4
1 (set) – CSIO is enabled and uses port H pin 4.
0 (clear) – CSIO is disabled and port H pin 4 is a general-purpose I/O pin.
IOPL — I/O chip select polarity select
1 (set) – CSIO is active high.
0 (clear) – CSIO is active low.
IOCSA — I/O chip select address valid
1 (set) – CSIO is valid during address valid time.
0 (clear) – CSIO is valid during E-clock high time.
IOSZ — I/O chip select size select
1 (set) – CSIO size is 8K at $0000–$1FFF.
0 (clear) – CSIO size is 4K at $1000–$1FFF.
GCSPR — General-purpose chip select priority (refer to Table 4-12)
1 (set) – General-purpose chip selects have priority over program chip select.
0 (clear) – Program chip select has priority over general-purpose chip selects.
PCSEN — Program chip select enable
1 (set) – CSPROG is enabled out of reset and uses port H pin 7.
0 (clear) – CSPROG is disabled and port H pin 7 is a general-purpose I/O pin.
PCSZA and PCSZB — Program chip select size (A or B)
Table 4-13 Program chip select size
PCSZA PCSZB
0
0
0
1
1
0
1
1
Size (bytes)
64K
32K
16K
8K
Address range
$0000 – $FFFF
$8000 – $FFFF
$C000 – $FFFF
$E000 – $FFFF
4-34
OPERATING MODES AND ON-CHIP MEMORY
MC68HC11KW1