mc68hc916y3 Freescale Semiconductor, Inc, mc68hc916y3 Datasheet - Page 397

• Manufacturer Part Number: mc68hc916y3
• Description: Mc68hc16y3 16 Bit Microcontroller
• Manufacturer: Freescale Semiconductor, Inc

CSPAR1 — Chip-Select Pin Assignment Register 1
MC68HC16Y3/916Y3
USER’S MANUAL
NOTES:
15
0
0
RESET:
1. Refer to Table D-11 for CSPAR1 reset state information.
CSPAR1 contains five 2-bit fields that determine the functions of corresponding chip-
select pins. Bits [15:10] are not used. These bits always read zero; writes have no
effect. Table D-10 shows CSPAR1 pin assignments, including alternate functions that
can be enabled by data bus mode selection during reset.
The reset state of DATA[7:3] determines whether pins controlled by CSPAR1 are ini-
tially configured as high-order address lines or chip-selects. Table D-11 shows the
correspondence between DATA[7:3] and the reset configuration of CS[10:6]/
ADDR[23:19]. This register may be read or written at any time. After reset, software
may enable one or more pins as discrete outputs.
DATA7
14
0
0
1
1
1
1
1
0
CSPAR1 Field
13
NOTES:
0
0
CS10PA[1:0]
DATA6
CS9PA[1:0]
CS8PA[1:0]
CS7PA[1:0]
CS6PA[1:0]
1. On the CPU16, ADDR[23:20] follow the logic state of ADDR19 unless externally
Data Bus Pins at Reset
X
1
1
1
1
0
driven.
12
0
0
DATA5
Table D-11 Reset Pin Function of CS[10:6]
Freescale Semiconductor, Inc.
X
X
1
1
1
0
11
Table D-10 CSPAR1 Pin Assignments
0
0
For More Information On This Product,
Chip-Select Signal
10
DATA4
0
0
CS10
X
X
X
1
1
0
CS9
CS8
CS7
CS6
Go to: www.freescale.com
DATA7
REGISTER SUMMARY
CS10PA[1:0]
9
DATA3
1
X
X
X
X
1
0
8
1
Alternate Signal
ADDR23
ADDR23 ADDR22 ADDR21 ADDR20 ADDR19
DATA
[7:6]
CS10/
CS10
CS10
CS10
CS10
CS10
CS9PA[1:0]
7
ADDR23
ADDR22
ADDR21
ADDR20
ADDR19
1
Chip-Select/Address Bus Pin Function
6
1
ADDR22
ADDR22 ADDR21 ADDR20 ADDR19
1
1
1
1
CS9/
CS9
CS9
CS9
CS9
DATA
[7:5]
CS8PA[1:0]
5
1
ADDR21
ADDR21 ADDR20 ADDR19
Discrete Output
CS8/
CS8
CS8
CS8
4
1
ECLK
PC6
PC5
PC4
PC3
DATA
[7:4]
CS7PA[1:0]
ADDR20
ADDR20 ADDR19
3
1
CS7/
CS7
CS7
2
1
ADDR19
ADDR19
$YFFA46
MOTOROLA
CS6/
CS6
DATA
[7:3]
CS6PA[1:0]
1
1
D-19
0
1