C8051F047R Silicon Labs, C8051F047R Datasheet - Page 193

• Manufacturer Part Number: C8051F047R
• Description: 8-bit Microcontrollers - MCU 25 MIPS 32KB 10ADC
• Manufacturer: Silicon Labs

Specifications of C8051F047R

• Product Category: 8-bit Microcontrollers - MCU
• Core: 8051
• Data Bus Width: 8 bit
• Maximum Clock Frequency: 25 MHz
• Program Memory Size: 32 KB
• Data Ram Size: 4.25 KB
• On-chip Adc: Yes
• Operating Supply Voltage: 2.7 V to 3.6 V
• Package / Case: TQFP-64
• Mounting Style: SMD/SMT
• A/d Bit Size: 10 bit
• A/d Channels Available: 13
• Data Rom Size: 64 KB
• Interface Type: CAN, SMBus, SPI, UART
• Maximum Operating Temperature: + 85 C
• Minimum Operating Temperature: - 40 C
• Number Of Programmable I/os: 32
• Number Of Timers: 16 bit
• Processor Series: C8051
• Program Memory Type: Flash
• Factory Pack Quantity: 500
• Supply Voltage - Max: 3.6 V
• Supply Voltage - Min: 2.7 V

16.5. Memory Mode Selection
The external data memory space can be configured in one of four modes, shown in Figure 16.3, based on
the EMIF Mode bits in the EMI0CF register (SFR Definition 16.2). These modes are summarized below.
More information about the different modes can be found in
16.5.1. Internal XRAM Only
When EMI0CF.[3:2] are set to ‘00’, all MOVX instructions will target the internal XRAM space on the
device. Memory accesses to addresses beyond the populated space will wrap on 4k boundaries. As an
example, the addresses 0x1000 and 0x2000 both evaluate to address 0x0000 in on-chip XRAM space.
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•
16.5.2. Split Mode without Bank Select
When EMI0CF.[3:2] are set to ‘01’, the XRAM memory map is split into two areas, on-chip space and off-
chip space.
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•
•
•
EMI0CF[3:2] = 00
On-Chip XRAM
On-Chip XRAM
On-Chip XRAM
On-Chip XRAM
On-Chip XRAM
On-Chip XRAM
8-bit MOVX operations use the contents of EMI0CN to determine the high-byte of the effective address
and R0 or R1 to determine the low-byte of the effective address.
16-bit MOVX operations use the contents of the 16-bit DPTR to determine the effective address.
Effective addresses below the 4k boundary will access on-chip XRAM space.
Effective addresses above the 4k boundary will access off-chip space.
8-bit MOVX operations use the contents of EMI0CN to determine whether the memory access is on-
chip or off-chip. However, in the “No Bank Select” mode, an 8-bit MOVX operation will not drive the
upper 8-bits A[15:8] of the Address Bus during an off-chip access. This allows the user to manipulate
the upper address bits at will by setting the Port state directly via the port latches. This behavior is in
contrast with “Split Mode with Bank Select” described below. The lower 8-bits of the Address Bus
A[7:0] are driven, determined by R0 or R1.
16-bit MOVX operations use the contents of DPTR to determine whether the memory access is on-
chip or off-chip, and unlike 8-bit MOVX operations, the full 16-bits of the Address Bus A[15:0] are
driven during the off-chip transaction.
0xFFFF
0x0000
EMI0CF[3:2] = 01
(No Bank Select)
On-Chip XRAM
Figure 16.3. EMIF Operating Modes
Off-Chip
Memory
0xFFFF
0x0000
Rev. 1.5
EMI0CF[3:2] = 10
On-Chip XRAM
(Bank Select)
C8051F040/1/2/3/4/5/6/7
Off-Chip
Memory
Section “16.6. Timing” on page
0xFFFF
0x0000
EMI0CF[3:2] = 11
Off-Chip
Memory
194.
0xFFFF
0x0000
193