C8051F330DK Silicon Laboratories Inc, C8051F330DK Datasheet - Page 82

• Manufacturer Part Number: C8051F330DK
• Description: DEV KIT FOR C8051F330/F331
• Manufacturer: Silicon Laboratories Inc
• Type: MCUr

Specifications of C8051F330DK

• Contents: Evaluation Board, Power Supply, USB Cables, Adapter and Documentation
• Processor To Be Evaluated: C8051F33x
• Interface Type: RS-232
• Operating Supply Voltage: 7 V to 15 V
• Silicon Manufacturer: Silicon Labs
• Core Architecture: 8051
• Silicon Core Number: C8051F330
• Silicon Family Name: C8051F33x
• Lead Free Status / RoHS Status: Contains lead / RoHS non-compliant
• For Use With/related Products: Silicon Laboratories C8051F330, C8051F331
• Lead Free Status / Rohs Status: Lead free / RoHS Compliant
• Other names: 336-1264

9.3.
The CIP-51 includes an extended interrupt system supporting a total of 13 interrupt sources with two prior-
ity levels. The allocation of interrupt sources between on-chip peripherals and external inputs pins varies
according to the specific version of the device. Each interrupt source has one or more associated interrupt-
pending flag(s) located in an SFR. When a peripheral or external source meets a valid interrupt condition,
the associated interrupt-pending flag is set to logic 1.
If interrupts are enabled for the source, an interrupt request is generated when the interrupt-pending flag is
set. As soon as execution of the current instruction is complete, the CPU generates an LCALL to a prede-
termined address to begin execution of an interrupt service routine (ISR). Each ISR must end with an RETI
instruction, which returns program execution to the next instruction that would have been executed if the
interrupt request had not occurred. If interrupts are not enabled, the interrupt-pending flag is ignored by the
hardware and program execution continues as normal. (The interrupt-pending flag is set to logic 1 regard-
less of the interrupt's enable/disable state.)
Each interrupt source can be individually enabled or disabled through the use of an associated interrupt
enable bit in an SFR (IE–EIE1). However, interrupts must first be globally enabled by setting the EA bit
(IE.7) to logic 1 before the individual interrupt enables are recognized. Setting the EA bit to logic 0 disables
all interrupt sources regardless of the individual interrupt-enable settings.
Note: Any instruction that clears the EA bit should be immediately followed by an instruction that has two
or more opcode bytes. For example:
// in 'C':
EA = 0; // clear EA bit.
Bits7–0: ACC: Accumulator.
Bits7–0: B: B Register.
ACC.7
R/W
R/W
B.7
Bit7
Bit7
Interrupt Handler
This register is the accumulator for arithmetic operations.
This register serves as a second accumulator for certain arithmetic operations.
ACC.6
R/W
R/W
B.6
Bit6
Bit6
ACC.5
SFR Definition 9.5. ACC: Accumulator
R/W
R/W
B.5
Bit5
Bit5
SFR Definition 9.6. B: B Register
ACC.4
R/W
R/W
B.4
Bit4
Bit4
Rev. 1.7
ACC.3
R/W
R/W
B.3
Bit3
Bit3
ACC.2
R/W
R/W
Bit2
B.2
Bit2
C8051F330/1/2/3/4/5
ACC.1
R/W
R/W
B.1
Bit1
Bit1
(bit addressable)
(bit addressable)
ACC.0
R/W
R/W
B.0
Bit0
Bit0
SFR Address:
SFR Address:
00000000
00000000
Reset Value
Reset Value
0xE0
0xF0
85