MC68HC16Z1 Datasheet, PDF (384/500 Pages) Freescale Semiconductor, Inc – M68HC16Z Series

Freescale Semiconductor, Inc.
NOTE
When changing a port E pin from an output to an input, the pin will
drive high for approximately four milliseconds. This ensures that the
shared bus control signal will be in a negated state before the pin be-
comes an input.
D.2.8 Port E Pin Assignment Register
PEPAR — Port E Pin Assignment
15
RESET:
NOT USED
$YFFA16
8
7
6
5
4
3
2
1
0
PEPA7 PEPA6 PEPA5 PEPA4 PEPA3 PEPA2 PEPA1 PEPA0
DATA8 DATA8 DATA8 DATA8 DATA8 DATA8 DATA8 DATA8
This register determines the function of port E pins. Setting a bit assigns the corre-
sponding pin to a bus control signal; clearing a bit assigns the pin to I/O port E. PE3 is
not connected to a pin. PEPA3 can be read and written, but has no function. Bits [15:8]
are unimplemented and will always read zero.
Table D-4 displays port E pin assignments.
Table D-4 Port E Pin Assignments
PEPAR Bit
Port E Signal
Bus Control Signal
PEPA7
PE7
SIZ1
PEPA6
PE6
SIZ0
PEPA5
PE5
AS
PEPA4
PE4
DS
PEPA3
PE3
—¹
PEPA2
PE2
AVEC
PEPA1
PE1
DSACK1
PEPA0
PE0
DSACK0
NOTES:
1. The CPU16 does not support the RMC function for this pin. This bit is not
connected to a pin for I/O usage.
D.2.9 Port F Data Register
PORTF0 — Port F Data Register 0
PORTF1 — Port F Data Register 1
15
RESET:
NOT USED
$YFFA18
$YFFA1A
8
7
6
5
4
3
2
1
0
PF7 PF6 PF5 PF4 PF3 PF2 PF1 PF0
U
U
U
U
U
U
U
U
This register can be accessed in two locations and can be read or written at any time.
A write to this register is stored in an internal data latch, and if any pin in the corre-
D-10
REGISTER SUMMARY
For More Information On This Product,
Go to: www.freescale.com
M68HC16 Z SERIES
USER’S MANUAL