Datasheet

Chapter 7 Keyboard Interrupt (S08KBIV2)
MC9S08LC60 Series Data Sheet: Technical Data, Rev. 4
100 Freescale Semiconductor
7.3.3 KBIx Edge Select Register (KBIxES)
KBIxES contains the edge select control bits.
7.4 Functional Description
This on-chip peripheral module is called a keyboard interrupt (KBI) module because originally it was
designed to simplify the connection and use of row-column matrices of keyboard switches. However, these
inputs are also useful as extra external interrupt inputs and as an external means of waking the MCU from
stop or wait low-power modes.
The KBI module allows up to eight pins to act as additional interrupt sources. Writing to the KBIPEn bits
in the keyboard interrupt pin enable register (KBIxPE) independently enables or disables each KBI pin.
Each KBI pin can be configured as edge sensitive or edge and level sensitive based on the KBMOD bit in
the keyboard interrupt status and control register (KBIxSC). Edge sensitive can be software programmed
to be either falling or rising; the level can be either low or high. The polarity of the edge or edge and level
sensitivity is selected using the KBEDGn bits in the keyboard interrupt edge select register (KBIxES).
76543210
R
KBIPE7 KBIPE6 KBIPE5 KBIPE4 KBIPE3 KBIPE2 KBIPE1 KBIPE0
W
Reset: 0 0 0 0 0 0 0 0
Figure 7-4. KBIx Pin Enable Register
Table 7-3. KBIxPE Register Field Descriptions
Field Description
7:0
KBIPEn
Keyboard Pin Enables — Each of the KBIPEn bits enable the corresponding keyboard interrupt pin.
0 Pin not enabled as keyboard interrupt.
1 Pin enabled as keyboard interrupt.
76543210
R
KBEDG7 KBEDG6 KBEDG5 KBEDG4 KBEDG3 KBEDG2 KBEDG1 KBEDG0
W
Reset: 0 0 0 0 0 0 0 0
Figure 7-5. KBIx Edge Select Register
Table 7-4. KBIxES Register Field Descriptions
Field Description
7:0
KBEDGn
Keyboard Edge Selects — Each of the KBEDGn bits selects the falling edge/low level or rising edge/high level
function of the corresponding pin).
0 Falling edge/low level.
1 Rising edge/high level.