MC9S08GT16CFB Freescale Semiconductor, MC9S08GT16CFB Datasheet - Page 147

• Manufacturer Part Number: MC9S08GT16CFB
• Manufacturer: Freescale Semiconductor

Specifications of MC9S08GT16CFB

• Cpu Family: HCS08
• Device Core Size: 8b
• Frequency (max): 20MHz
• Interface Type: SCI/SPI
• Program Memory Type: Flash
• Program Memory Size: 16KB
• Total Internal Ram Size: 1KB
• # I/os (max): 36
• Number Of Timers - General Purpose: 4
• Operating Supply Voltage (typ): 2.5/3.3V
• Operating Supply Voltage (max): 3.6V
• Operating Supply Voltage (min): 2.08V
• On-chip Adc: 8-chx10-bit
• Instruction Set Architecture: CISC
• Operating Temp Range: -40C to 85C
• Operating Temperature Classification: Industrial
• Mounting: Surface Mount
• Pin Count: 44
• Package Type: PQFP
• Lead Free Status / Rohs Status: Not Compliant

9.3
Figure 9-3
The KBI module allows up to eight pins to act as additional interrupt sources. Four of these pins allow
falling-edge sensing while the other four can be configured for either rising-edge sensing or falling-edge
sensing. The sensing mode for all eight pins can also be modified to detect edges and levels instead of only
edges.
9.4
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 up the MCU
from stop or wait low-power modes.
9.4.1
The KBIPEn control bits in the KBI1PE register allow a user to enable (KBIPEn = 1) any combination of
KBI-related port pins to be connected to the KBI module. Pins corresponding to 0s in KBI1PE are
general-purpose I/O pins that are not associated with the KBI module.
9.4.2
Synchronous logic is used to detect edges. Prior to detecting an edge, enabled keyboard inputs in a KBI
module must be at the deasserted logic level.
A falling edge is detected when an enabled keyboard input signal is seen as a logic 1 (the deasserted level)
during one bus cycle and then a logic 0 (the asserted level) during the next cycle.
Freescale Semiconductor
KBI1P0
KBI1P3
KBI1P4
KBI1Pn
KBEDGn
KBEDG4
KBI Block Diagram
Keyboard Interrupt (KBI) Module
shows the block diagram for a KBI module.
Pin Enables
Edge and Level Sensitivity
0
1
0
1
S
S
KBIPE0
KBIPE3
KBIPE4
KBIPEn
MC9S08GB/GT Data Sheet, Rev. 2.3
Figure 9-3. KBI Block Diagram
KBIMOD
V
DD
D
CK
CLR
Q
INTERRUPT FF
KEYBOARD
KBACK
RESET
STOP
SYNCHRONIZER
BUSCLK
STOP BYPASS
KBIE
KBI Block Diagram
KBF
KEYBOARD
INTERRUPT
REQUEST
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