收藏本站
参数资料
型号： DV164136
厂商： Microchip Technology
文件页数： 79/107页
文件大小： 0K
描述： DEVELOPMENT KIT FOR PIC18
产品培训模块： PIC18 J Series MCU Overview
标准包装： 1
系列： PIC®
类型： MCU
适用于相关产品： PIC18F8722，PIC18F87J11
所含物品： 板，线缆，CD，PICkit? 3 个编程器，电源
产品目录页面： 659 (CN2011-ZH PDF)
相关产品： PIC18F87J11-I/PT-ND - IC PIC MCU FLASH 64KX16 80TQFP
PIC18F87J11T-I/PTTR-ND - IC PIC MCU FLASH 64KX16 80TQFP
PIC18F8722T-E/PT-ND - IC PIC MCU FLASH 64KX16 80TQFP
PIC18F8722-E/PT-ND - IC PIC MCU FLASH 64KX16 80TQFP
PIC18F8722T-I/PT-ND - IC PIC MCU FLASH 64KX16 80TQFP
PIC18F8722-I/PT-ND - IC PIC MCU FLASH 64KX16 80TQFP
2007-2012 Microchip Technology Inc.
DS39778E-page 73
PIC18F87J11 FAMILY
6.1.6.4
Stack Full and Underflow Resets
Device Resets on stack overflow and stack underflow
conditions are enabled by setting the STVREN bit in
Configuration Register 1L. When STVREN is set, a full
or underflow condition will set the appropriate STKFUL
or STKUNF bit and then cause a device Reset. When
STVREN is cleared, a full or underflow condition will set
the appropriate STKFUL or STKUNF bit, but not cause
a device Reset. The STKFUL or STKUNF bits are
cleared by the user software or a Power-on Reset.
6.1.7
FAST REGISTER STACK
A Fast Register Stack is provided for the STATUS,
WREG and BSR registers to provide a “fast return”
option for interrupts. This stack is only one level deep
and is neither readable nor writable. It is loaded with the
current value of the corresponding register when the
processor vectors for an interrupt. All interrupt sources
will push values into the Stack registers. The values in
the registers are then loaded back into the working
registers if the RETFIE, FAST instruction is used to
return from the interrupt.
If both low and high-priority interrupts are enabled, the
Stack registers cannot be used reliably to return from
low-priority interrupts. If a high-priority interrupt occurs
while servicing a low-priority interrupt, the Stack
register values stored by the low-priority interrupt will
be overwritten. In these cases, users must save the key
registers in software during a low-priority interrupt.
If interrupt priority is not used, all interrupts may use the
Fast Register Stack for returns from interrupt. If no
interrupts are used, the Fast Register Stack can be
used to restore the STATUS, WREG and BSR registers
at the end of a subroutine call. To use the Fast Register
Stack for a subroutine call, a CALL label, FAST
instruction must be executed to save the STATUS,
WREG and BSR registers to the Fast Register Stack. A
RETURN, FAST
instruction is then executed to restore
these registers from the Fast Register Stack.
Example 6-1 shows a source code example that uses
the Fast Register Stack during a subroutine call and
return.
EXAMPLE 6-1:
FAST REGISTER STACK
CODE EXAMPLE
6.1.8
LOOK-UP TABLES IN PROGRAM
MEMORY
There may be programming situations that require the
creation of data structures, or look-up tables, in
program memory. For PIC18 devices, look-up tables
can be implemented in two ways:
Computed GOTO
Table Reads
6.1.8.1
Computed GOTO
A computed GOTO is accomplished by adding an offset
to the Program Counter. An example is shown in
Example 6-2.
A look-up table can be formed with an ADDWF PCL
instruction and a group of RETLW nn instructions. The
W register is loaded with an offset into the table before
executing a call to that table. The first instruction of the
called routine is the ADDWF PCL instruction. The next
instruction executed will be one of the RETLW
nn
instructions that returns the value, ‘nn’, to the calling
function.
The offset value (in WREG) specifies the number of
bytes that the Program Counter should advance and
should be multiples of 2 (LSb = 0).
In this method, only one data byte may be stored in
each instruction location and room on the return
address stack is required.
EXAMPLE 6-2:
COMPUTED GOTO USING
AN OFFSET VALUE
6.1.8.2
Table Reads
A better method of storing data in program memory
allows two bytes of data to be stored in each instruction
location.
Look-up table data may be stored, two bytes per
program word, while programming. The Table Pointer
(TBLPTR) specifies the byte address and the Table
Latch (TABLAT) contains the data that is read from the
program memory. Data is transferred from program
memory, one byte at a time.
Table read operation is discussed further in
Section 7.1 “Table Reads and Table Writes”
.
CALL SUB1, FAST
;STATUS, WREG, BSR
;SAVED IN FAST REGISTER
;STACK
SUB1
RETURN FAST
;RESTORE VALUES SAVED
;IN FAST REGISTER STACK
MOVF
OFFSET, W
CALL
TABLE
ORG
nn00h
TABLE
ADDWF
PCL
RETLW
nnh
RETLW
nnh
RETLW
nnh
.
相关PDF资料
PDF描述
GBM25DCWT CONN EDGECARD 50POS DIP .156 SLD
GCM24DCTN CONN EDGECARD 48POS DIP .156 SLD
1435863-2 PATCHCORD CAT6 YLW/YLW BOOT 2'
1435862-2 PATCHCORD CAT6 RED/RED BOOT 2'
V48C5T50BF3 CONVERTER MOD DC/DC 5V 50W
相关代理商/技术参数
参数描述
DV164139 功能描述:开发板和工具包 - PIC / DSPIC Lo PIn Count USB Dev Kit (w/PICkit 3) RoHS:否 制造商:Microchip Technology 产品:Starter Kits 工具用于评估:chipKIT 核心:Uno32 接口类型: 工作电源电压:
DV17K3225T 制造商:SEI Stackpole Electronics Inc 功能描述:- Tape and Reel 制造商:SEI Stackpole Electronics Inc 功能描述:Var MOV 17VAC/22VDC 100A 27V 3225 SMD T/R
DV17K4032T 制造商:SEI Stackpole Electronics Inc 功能描述:VAR 17VAC 22VDC 250A 27V 4032 SMD - Tape and Reel 制造商:SEI Stackpole Electronics Inc 功能描述:Var MOV 17VAC/22VDC 250A 27V 4032 SMD T/R
DV18-145MB-3K 功能描述:端子 PIN -DSC 22-18 145X032 VYL RED RoHS:否 制造商:AVX 产品:Junction Box - Wire to Wire 系列:9826 线规:26-18 接线柱/接头大小: 绝缘: 颜色:Red 型式:Female 触点电镀:Tin over Nickel 触点材料:Beryllium Copper, Phosphor Bronze 端接类型:Crimp
DV18-145M-C 功能描述:端子 MALE BLADE ADAPT RoHS:否 制造商:AVX 产品:Junction Box - Wire to Wire 系列:9826 线规:26-18 接线柱/接头大小: 绝缘: 颜色:Red 型式:Female 触点电镀:Tin over Nickel 触点材料:Beryllium Copper, Phosphor Bronze 端接类型:Crimp
发布紧急采购，3分钟左右您将得到回复。

采购需求

(若只采购一条型号，填写一行即可)

发布成功！您可以继续发布采购。也可以进入我的后台，查看报价

发布成功！您可以继续发布采购。也可以进入我的后台，查看报价

*型号 *数量 厂商 批号 封装
添加更多采购

我的联系方式

*
*
*