MC68HC11A1 MOTOROLA [Motorola, Inc], MC68HC11A1 Datasheet - Page 6

• Manufacturer Part Number: MC68HC11A1
• Description: 8-Bit Microcontrollers
• Manufacturer: MOTOROLA [Motorola, Inc]

2 Operating Modes and Memory Maps
6
MOTOROLA
In single-chip operating mode, the MC68HC11A8 is a monolithic microcontroller without external ad-
dress or data buses.
In expanded multiplexed operating mode, the MCU can access a 64 Kbyte address space. The space
includes the same on-chip memory addresses used for single-chip mode plus external peripheral and
memory devices. The expansion bus is made up of ports B and C and control signals AS and R/W. The
address, R/W, and AS signals are active and valid for all bus cycles including accesses to internal mem-
ory locations. The following figure illustrates a recommended method of demultiplexing low-order ad-
dresses from data at port C.
MODB/V STBY
PA6/OC2/OC1
PA5/OC3/OC1
PA4/OC4/OC1
PA3/OC5/OC1
PA7/PAI/OC1
Figure 3 48-Pin DIP Pin Assignments
PE3/AN3
PE0/AN0
PE2/AN2
PB5/A13
PE1/AN1
PB7/A15
PB6/A14
PB4/A12
PB2/A10
PB3/A11
PA1/IC2
PA0/IC3
PA2/IC1
PB1/A9
PB0/A8
V RH
V RL
V SS
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
48
47
46
45
44
43
42
41
40
39
38
37
36
35
34
33
32
31
30
29
28
27
26
25
PD5/SS
PD4/SCK
PD3/MOSI
PD2/MISO
PD1/TxD
PD0/RxD
RESET
PC7/A7/D7
PC6/A6/D6
PC5/A5/D5
PC4/A4/D4
PC3/A3/D3
PC2/A2/D2
PC1/A1/D1
PC0/A0/D0
V DD
IRQ
XIRQ
XTAL
EXTAL
STRB/ R/W
E
STRA/AS
MODA/LIR
MC68HC11A8TS/D
MC68HC11A8