mc68hc916y3 Freescale Semiconductor, Inc, mc68hc916y3 Datasheet - Page 396

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

D.2.23 Chip-Select Pin Assignment Registers
CSPAR0 — Chip-Select Pin Assignment Register 0
D-18
MOTOROLA
15
0
0
RESET:
Chip-select pin assignment registers configure the chip-select pins for discrete I/O, an
alternate function, or as an 8-bit or 16-bit chip-select. The possible encodings for each
2-bit field in CSPAR[0:1] (except for CSBTPA[1:0]) are shown in Table D-8.
This register contains seven 2-bit fields that determine the function of corresponding
chip-select pins. Bits [15:14] are not used. These bits always read zero; writes have
no effect. CSPAR0 bit 1 always reads one; writes to CSPAR0 bit 1 have no effect. The
alternate functions can be enabled by data bus mode selection during reset. This
register may be read or written at any time. After reset, software may enable one or
more pins as discrete outputs.
Table D-9 shows CSPAR0 pin assignments.
14
0
0
DATA2
13
CS5PA[1:0]
CSPAR0 Field
CSBTPA[1:0]
CS5PA[1:0]
CS4PA[1:0]
CS3PA[1:0]
CS2PA[1:0]
CS1PA[1:0]
CS0PA[1:0]
12
1
Table D-8 Pin Assignment Field Encoding
DATA2
Freescale Semiconductor, Inc.
11
CS4PA[1:0]
Table D-9 CSPAR0 Pin Assignments
NOTES:
For More Information On This Product,
CSxPA[1:0]
Chip-Select Signal
1. Does not apply to the CSBOOT field.
00
01
10
11
10
1
CSBOOT
CS5
CS4
CS3
CS2
CS1
CS0
Go to: www.freescale.com
DATA2
REGISTER SUMMARY
CS3PA[1:0]
9
8
1
Chip-select (16-bit port)
Chip-select (8-bit port)
Alternate function
Alternate Signal
Discrete output
DATA1
Description
CS2PA[1:0]
7
BGACK
FC2
FC1
FC0
BG
BR
—
6
1
DATA1
1
1
CS1PA[1:0]
5
Discrete Output
4
1
PC2
PC1
PC0
—
—
—
—
DATA1
CS0PA[1:0]
3
MC68HC16Y3/916Y3
USER’S MANUAL
2
1
$YFFA44
CSBTPA[1:0]
1
1
DATA0
0