Datasheet

Chapter 6 Parallel Input/Output
MC9S08LC60 Series Data Sheet: Technical Data, Rev. 4
Freescale Semiconductor 89
6.2.4.2 Output Slew Rate Control Enable (PTBSE)
Slew rate control can be enabled for each port pin by setting the corresponding bit in the slew rate control
register (PTBSEn). When enabled, slew control limits the rate at which an output can transition in order
to reduce EMC emissions. Slew rate control has no effect on pins which are configured as inputs.
76543210
R
PTBPE7 PTBPE6 PTBPE5 PTBPE4 PTBPE3 PTBPE2 PTBPE1 PTBPE0
W
Reset 00000000
Figure 6-15. Pullup Enable for Port B (PTBPE)
Table 6-8. PTBPE Field Descriptions
Field Description
7:0
PTBPE[7:0]
Pullup Enable for Port B Bits — For port B pins that are inputs, these read/write control bits determine whether
internal pullup devices are enabled provided the corresponding PTBDDn is 0. For port B pins that are configured
as outputs, these bits are ignored and the internal pullup devices are disabled. When bit 0, 1, 3, 6, or 7 of port B
is enabled as KBI inputs and are configured to detect rising edges/high levels, the pullup enable bits enable
pulldown rather than pullup devices.
0 Internal pullup device disabled.
1 Internal pullup device enabled.
76543210
R
PTBSE7 PTBSE6 PTBSE5 PTBSE4 PTBSE3 PTBSE2 PTBSE1 PTBSE0
W
Reset 11111111
Figure 6-16. Slew Rate Control Enable for Port B (PTBSE)
Table 6-9. PTBSE Field Descriptions
Field Description
7:0
PTBSE[7:0]
Slew Rate Control Enable for Port B Bits — For port B pins that are outputs, these read/write control bits
determine whether the slew rate controlled outputs are enabled. For port B pins that are configured as inputs,
these bits are ignored.
0 Slew rate control disabled.
1 Slew rate control enabled.