PIC18F87J50-I/PT Microchip Technology, PIC18F87J50-I/PT Datasheet - Page 115

• Manufacturer Part Number: PIC18F87J50-I/PT
• Description: IC PIC MCU FLASH 64KX16 80TQFP
• Manufacturer: Microchip Technology
• Series: PIC® 18Fr

Specifications of PIC18F87J50-I/PT

• Program Memory Type: FLASH
• Program Memory Size: 128KB (64K x 16)
• Package / Case: 80-TFQFP
• Core Processor: PIC
• Core Size: 8-Bit
• Speed: 48MHz
• Connectivity: EBI/EMI, I²C, SPI, UART/USART, USB
• Peripherals: Brown-out Detect/Reset, LVD, POR, PWM, WDT
• Number Of I /o: 65
• Ram Size: 3.8K x 8
• Voltage - Supply (vcc/vdd): 2 V ~ 3.6 V
• Data Converters: A/D 12x10b
• Oscillator Type: Internal
• Operating Temperature: -40°C ~ 85°C
• Processor Series: PIC18F
• Core: PIC
• Data Bus Width: 8 bit
• Data Ram Size: 3936 B
• Interface Type: I2C, MSSP, SPI, EUSART
• Maximum Clock Frequency: 48 MHz
• Number Of Programmable I/os: 66
• Number Of Timers: 5
• Maximum Operating Temperature: + 100 C
• Mounting Style: SMD/SMT
• 3rd Party Development Tools: 52715-96, 52716-328, 52717-734, 52712-325, EWPIC18
• Development Tools By Supplier: PG164130, DV164035, DV244005, DV164005, PG164120, DM183032, DM183022, DV164136
• Minimum Operating Temperature: - 40 C
• On-chip Adc: 10 bit, 12 Channel
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• For Use With: AC162087 - HEADER MPLAB ICD2 18F87J50 68/84MA180021 - MODULE PLUG-IN 18F87J50 FS USBAC164328 - MODULE SKT FOR 80TQFP
• Eeprom Size: -
• Lead Free Status / Rohs Status: Lead free / RoHS Compliant

7.7
In 8-Bit Data Width mode, the External Memory Bus
operates only in Multiplexed mode; that is, data shares
the 8 Least Significant bits of the address bus.
Figure 7-6 shows an example of 8-Bit Multiplexed
mode for 80-pin devices. This mode is used for a single
8-bit memory connected for 16-bit operation. The
instructions will be fetched as two 8-bit bytes on a
shared data/address bus. The two bytes are sequen-
tially fetched within one instruction cycle (T
Therefore, the designer must choose external memory
devices according to timing calculations based on
1/2 T
ory speed selection, glue logic propagation delay times
must be considered, along with setup and hold times.
FIGURE 7-6:
© 2009 Microchip Technology Inc.
CY
(2 times the instruction rate). For proper mem-
8-Bit Data Width Mode
Note 1:
2:
PIC18F87J50
Upper order address bits are only used for 20-bit address width. The upper AD byte is used for all
address widths except 8-bit.
This signal only applies to table writes. See Section 6.1 “Table Reads and Table Writes”.
AD<15:8>
A<19:16>
8-BIT MULTIPLEXED MODE EXAMPLE
AD<7:0>
WRL
ALE
BA0
CE
OE
(1)
(1)
CY
).
373
PIC18F87J50 FAMILY
The Address Latch Enable (ALE) pin indicates that the
address bits, AD<15:0>, are available on the external
memory interface bus. The Output Enable signal (OE)
will enable one byte of program memory for a portion of
the instruction cycle, then BA0 will change and the
second byte will be enabled to form the 16-bit instruc-
tion word. The Least Significant bit of the address, BA0,
must be connected to the memory devices in this
mode. The Chip Enable signal (CE) is active at any
time that the microcontroller accesses external
memory, whether reading or writing. It is inactive
(asserted high) whenever the device is in Sleep mode.
This generally includes basic EPROM and Flash
devices. It allows table writes to byte-wide external
memories.
D<7:0>
A<19:0>
D<15:8>
Address Bus
Data Bus
Control Lines
A0
OE
A<x:1>
D<7:0>
CE
WR
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