參數(shù)資料
型號: TOOLSTICK300DC
廠商: Silicon Laboratories Inc
文件頁數(shù): 149/178頁
文件大?。?/td> 0K
描述: TOOLSTICK DAUGHTER CARD
標準包裝: 1
系列: ToolStick
類型: MCU
適用于相關(guān)產(chǎn)品: C8051F300
所含物品: 子卡
C8051F300/1/2/3/4/5
72
Rev. 2.9
8.3.
Interrupt Handler
The CIP-51 includes an extended interrupt system supporting a total of 12 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
EA = 0;
// ... followed by another 2-byte opcode
; in assembly:
CLR
EA
; clear EA bit
CLR
EA
; ... followed by another 2-byte opcode
If an interrupt is posted during the execution phase of a "CLR EA" opcode (or any instruction which clears
the EA bit), and the instruction is followed by a single-cycle instruction, the interrupt may be taken. How-
ever, a read of the EA bit will return a '0' inside the interrupt service routine. When the "CLR EA" opcode is
followed by a multi-cycle instruction, the interrupt will not be taken.
Some interrupt-pending flags are automatically cleared by the hardware when the CPU vectors to the ISR.
However, most are not cleared by the hardware and must be cleared by software before returning from the
ISR. If an interrupt-pending flag remains set after the CPU completes the return-from-interrupt (RETI)
instruction, a new interrupt request will be generated immediately and the CPU will reenter the ISR after
the completion of the next instruction.
8.3.1. MCU Interrupt Sources and Vectors
The MCUs support 12 interrupt sources. Software can simulate an interrupt by setting any interrupt-pend-
ing flag to logic 1. If interrupts are enabled for the flag, an interrupt request will be generated and the CPU
will vector to the ISR address associated with the interrupt-pending flag. MCU interrupt sources, associ-
ated vector addresses, priority order and control bits are summarized in Table 8.4 on page 74. Refer to the
datasheet section associated with a particular on-chip peripheral for information regarding valid interrupt
conditions for the peripheral and the behavior of its interrupt-pending flag(s).
相關(guān)PDF資料
PDF描述
TOOLSTICK411DC TOOLSTICK DAUGHTER CARD
TOOLSTICK336DC DAUGHTER CARD TOOLSTICK C8051F33
SDR-2 SCOTCH CODE REFILL # 2
0210490198 CABLE JUMPER 1.25MM .127M 14POS
RSM08DRTH CONN EDGECARD 16POS DIP .156 SLD
相關(guān)代理商/技術(shù)參數(shù)
參數(shù)描述
TOOLSTICK300PP 功能描述:插座和適配器 Dev Tool for C8051F30X MCUs RoHS:否 制造商:Silicon Labs 產(chǎn)品:Adapter 用于:EM35x
TOOLSTICK300SPP 功能描述:插座和適配器 TS for F300-F305 SOIC 14 MCUs RoHS:否 制造商:Silicon Labs 產(chǎn)品:Adapter 用于:EM35x
TOOLSTICK310PP 功能描述:插座和適配器 C8051F310/12/14 F361 F364 F366 F368 RoHS:否 制造商:Silicon Labs 產(chǎn)品:Adapter 用于:EM35x
TOOLSTICK311DC 功能描述:子卡和OEM板 ToolStick C8051F311 Daughter Card RoHS:否 制造商:BeagleBoard by CircuitCo 產(chǎn)品:BeagleBone LCD4 Boards 用于:BeagleBone - BB-Bone - Open Source Development Kit
TOOLSTICK311PP 功能描述:插座和適配器 C8051F311/13/15 F362 F365 F367 F369 RoHS:否 制造商:Silicon Labs 產(chǎn)品:Adapter 用于:EM35x