C8051F704-GQR Silicon Labs, C8051F704-GQR Datasheet - Page 111
![no-image](/images/no-image-200.jpg)
C8051F704-GQR
Manufacturer Part Number
C8051F704-GQR
Description
8-bit Microcontrollers - MCU 15kB 32B EEPROM ADC Cap Sense
Manufacturer
Silicon Labs
Datasheet
1.C8051F709-GQR.pdf
(306 pages)
Specifications of C8051F704-GQR
Rohs
yes
Core
8051
Data Bus Width
8 bit
Processor Series
C8051
Available stocks
Company
Part Number
Manufacturer
Quantity
Price
Company:
Part Number:
C8051F704-GQR
Manufacturer:
Silicon Laboratories Inc
Quantity:
10 000
- Current page: 111 of 306
- Download datasheet (2Mb)
18. External Data Memory Interface and On-Chip XRAM
For C8051F70x/71x devices, 256 B of RAM are included on-chip and mapped into the external data mem-
ory space (XRAM). Additionally, an External Memory Interface (EMIF) is available on the
C8051F700/1/2/3/8/9 and C8051F710/1 devices, which can be used to access off-chip data memories and
memory-mapped devices connected to the GPIO ports. The external memory space may be accessed
using the external move instruction (MOVX) and the data pointer (DPTR), or using the MOVX indirect
addressing mode using R0 or R1. If the MOVX instruction is used with an 8-bit address operand (such as
@R1), then the high byte of the 16-bit address is provided by the External Memory Interface Control Reg-
ister (EMI0CN, shown in SFR Definition 18.1).
Note: The MOVX instruction can also be used for writing to the Flash memory. See Section “
18.1. Accessing XRAM
The XRAM memory space is accessed using the MOVX instruction. The MOVX instruction has two forms,
both of which use an indirect addressing method. The first method uses the Data Pointer, DPTR, a 16-bit
register which contains the effective address of the XRAM location to be read from or written to. The sec-
ond method uses R0 or R1 in combination with the EMI0CN register to generate the effective XRAM
address. Examples of both of these methods are given below.
18.1.1. 16-Bit MOVX Example
The 16-bit form of the MOVX instruction accesses the memory location pointed to by the contents of the
DPTR register. The following series of instructions reads the value of the byte at address 0x1234 into the
accumulator A:
The above example uses the 16-bit immediate MOV instruction to set the contents of DPTR. Alternately,
the DPTR can be accessed through the SFR registers DPH, which contains the upper 8-bits of DPTR, and
DPL, which contains the lower 8-bits of DPTR.
18.1.2. 8-Bit MOVX Example
The 8-bit form of the MOVX instruction uses the contents of the EMI0CN SFR to determine the upper 8-bits
of the effective address to be accessed and the contents of R0 or R1 to determine the lower 8-bits of the
effective address to be accessed. The following series of instructions read the contents of the byte at
address 0x1234 into the accumulator A.
page
MOV
MOVX
MOV
MOV
MOVX
148
for details. The MOVX instruction accesses XRAM by default.
DPTR, #1234h
A, @DPTR
EMI0CN, #12h
R0, #34h
a, @R0
; load DPTR with 16-bit address to read (0x1234)
; load contents of 0x1234 into accumulator A
; load high byte of address into EMI0CN
; load low byte of address into R0 (or R1)
; load contents of 0x1234 into accumulator A
Rev. 1.0
C8051F70x/71x
22. Flash Memory
” on
111
Related parts for C8051F704-GQR
Image
Part Number
Description
Manufacturer
Datasheet
Request
R
![CP2102EK](/photos/9/3/90395/cp2102ek_tmb.jpg)
Part Number:
Description:
KIT EVALUATION FOR CP2102
Manufacturer:
Silicon Laboratories Inc
Datasheet:
![CP2103EK](/photos/9/6/90669/cp2103ek_tmb.jpg)
Part Number:
Description:
KIT EVAL FOR CP2103 USB TO UART
Manufacturer:
Silicon Laboratories Inc
Datasheet:
![CP2201EK](/photos/9/9/90977/cp2201ek_tmb.jpg)
Part Number:
Description:
KIT EVAL FOR CP2201 ETH CTRLR
Manufacturer:
Silicon Laboratories Inc
Datasheet:
![CAPTOUCHSENSEDC](/photos/9/20/92001/captouchsensedc_tmb.jpg)
Part Number:
Description:
DAUGHTER CARD CAP TOUCH SENSE
Manufacturer:
Silicon Laboratories Inc
Datasheet:
![CAPTOUCHSENSESK](/photos/9/20/92002/captouchsensesk_tmb.jpg)
Part Number:
Description:
KIT STARTER CAP TOUCH SENSE
Manufacturer:
Silicon Laboratories Inc
Datasheet:
![C8051F320DK](/photos/9/20/92068/c8051f320dk_tmb.jpg)
Part Number:
Description:
DEV KIT FOR C8051F320/F321
Manufacturer:
Silicon Laboratories Inc
Datasheet:
![C8051F120DK](/photos/9/20/92070/c8051f120dk_tmb.jpg)
Part Number:
Description:
DEVKIT-F120/21/22/23/24/25/26/27
Manufacturer:
Silicon Laboratories Inc
Datasheet:
![C8051F310DK](/photos/9/23/92300/c8051f310dk_tmb.jpg)
Part Number:
Description:
DEV KIT FOR C8051F310/F311
Manufacturer:
Silicon Laboratories Inc
Datasheet:
![C8051F226DK](/photos/9/23/92302/c8051f226dk_tmb.jpg)
Part Number:
Description:
DEV KIT F220/221/226/230/231/236
Manufacturer:
Silicon Laboratories Inc
Datasheet:
![C8051F300DK](/photos/9/23/92305/c8051f300dk_tmb.jpg)
Part Number:
Description:
DEV KIT F300/301/302/303/304/305
Manufacturer:
Silicon Laboratories Inc
Datasheet:
![C8051F330DK](/photos/9/23/92306/c8051f330dk_tmb.jpg)
Part Number:
Description:
DEV KIT FOR C8051F330/F331
Manufacturer:
Silicon Laboratories Inc
Datasheet:
![C8051F005DK](/photos/9/23/92307/c8051f005dk_tmb.jpg)
Part Number:
Description:
DEV KIT FOR F005/006/007
Manufacturer:
Silicon Laboratories Inc
Datasheet:
![C8051F020DK](/photos/9/23/92314/c8051f020dk_tmb.jpg)
Part Number:
Description:
DEV KIT FOR F020/F021/F022/F023
Manufacturer:
Silicon Laboratories Inc
Datasheet:
![C8051F340DK](/photos/9/23/92323/c8051f340dk_tmb.jpg)
Part Number:
Description:
KIT DEV FOR C8051F34X
Manufacturer:
Silicon Laboratories Inc
Datasheet:
![C8051F410DK](/photos/9/23/92324/c8051f410dk_tmb.jpg)
Part Number:
Description:
KIT DEV FOR C8051F41X
Manufacturer:
Silicon Laboratories Inc
Datasheet: