MC9S08SG8 Datasheet, PDF (80/310 Pages) Freescale Semiconductor, Inc – Microcontrollers

Chapter 6 Parallel Input/Output Control
6.6.1.5 Port A Drive Strength Selection Register (PTADS)
7
6
5
4
3
2
1
0
R
0
0
R
R
PTADS3
PTADS2
PTADS1
PTADS0
W
Reset:
0
0
0
0
0
0
0
0
Figure 6-7. Drive Strength Selection for Port A Register (PTADS)
Table 6-6. PTADS Register Field Descriptions
Field
Description
5:4
Reserved Bits — These bits are unused on this MCU, writes have no affect and could read as 1s or 0s.
Reserved
3:0
PTADS[3:0]
Output Drive Strength Selection for Port A Bits — Each of these control bits selects between low and high
output drive for the associated PTA pin. For port A pins that are configured as inputs, these bits have no effect.
0 Low output drive strength selected for port A bit n.
1 High output drive strength selected for port A bit n.
6.6.1.6 Port A Interrupt Status and Control Register (PTASC)
7
6
5
4
3
2
1
0
R
0
0
0
0
PTAIF
0
PTAIE
PTAMOD
W
PTAACK
Reset:
0
0
0
0
0
0
0
0
Figure 6-8. Port A Interrupt Status and Control Register (PTASC)
Table 6-7. PTASC Register Field Descriptions
Field
Description
3
PTAIF
2
PTAACK
1
PTAIE
0
PTAMOD
Port A Interrupt Flag — PTAIF indicates when a port A interrupt is detected. Writes have no effect on PTAIF.
0 No port A interrupt detected.
1 Port A interrupt detected.
Port A Interrupt Acknowledge — Writing a 1 to PTAACK is part of the flag clearing mechanism. PTAACK
always reads as 0.
Port A Interrupt Enable — PTAIE determines whether a port A interrupt is requested.
0 Port A interrupt request not enabled.
1 Port A interrupt request enabled.
Port A Detection Mode — PTAMOD (along with the PTAES bits) controls the detection mode of the port A
interrupt pins.
0 Port A pins detect edges only.
1 Port A pins detect both edges and levels.
MC9S08SG8 MCU Series Data Sheet, Rev. 0
80
PRELIMINARY
Freescale Semiconductor