20-668-0024 Rabbit Semiconductor, 20-668-0024 Datasheet - Page 80

• Manufacturer Part Number: 20-668-0024
• Description: IC CPU RABBIT4000 128-LQFP
• Manufacturer: Rabbit Semiconductor

Specifications of 20-668-0024

• Processor Type: Rabbit 4000 8-bit
• Speed: 60MHz
• Voltage: 2.5V, 2.7V, 3V, 3.3V
• Mounting Type: Surface Mount
• Package / Case: 128-LQFP
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Features: -
• Other names: 20-668-0022; 316-1078

7.2.1 Registers
7.3 Dependencies
7.3.1 I/O Pins
The external interrupts can be enabled on pins PD0, PD1, PE0, PE1, PE4, and PE5. Each
pin is associated with a particular interrupt vector as shown in Table 7-1 below.
7.3.2 Clocks
The external interrupts are controlled by the peripheral clock. A pulse must be present for
at least three peripheral clock cycles to trigger an interrupt.
7.3.3 Interrupts
An external interrupt is generated whenever the selected edge occurs on an enabled pin.
The interrupt request is automatically cleared when the interrupt is handled.
The external interrupt vectors are in the EIR at offsets 0x000 and 0x010. They can be set
as Priority 1, 2, or 3 in the appropriate IxCR.
7.4 Operation
The following steps must be taken to enable the external interrupts:
1. Write the vector(s) to the interrupt service routine to the external interrupt table.
2. Configure IxCR to select which pins are enabled for external interrupts, what edges are
7.4.1 Example ISR
A sample interrupt handler is shown below.
70
Interrupt 0 Control Register
Interrupt 1 Control Register
detected on each pin, and the interrupt priority.
extInt_isr::
; respond to external interrupt here
; interrupt is automatically cleared by interrupt acknowledge
ipres
ret
Register Name
Interrupt 0
Interrupt 1
Vector
Table 7-1. Rabbit 4000 Interrupt Vectors
Register
I0CR
I1CR
Mnemonic
I0CR
I1CR
Rabbit 4000 Microprocessor User’s Manual
PD0, PE0, PE4
PD1, PE1, PE5
I/O Address
Pins
0x0098
0x0099
R/W
R/W
R/W
xx000000
xx000000
Reset