PIC18F4420T-I/PT Microchip Technology, PIC18F4420T-I/PT Datasheet - Page 24

• Manufacturer Part Number: PIC18F4420T-I/PT
• Description: IC,MICROCONTROLLER,8-BIT,PIC CPU,CMOS,TQFP,44PIN,PLASTIC
• Manufacturer: Microchip Technology
• Series: PIC® 18Fr

Specifications of PIC18F4420T-I/PT

• Rohs Compliant: YES
• Core Processor: PIC
• Core Size: 8-Bit
• Speed: 40MHz
• Connectivity: I²C, SPI, UART/USART
• Peripherals: Brown-out Detect/Reset, HLVD, POR, PWM, WDT
• Number Of I /o: 36
• Program Memory Size: 16KB (8K x 16)
• Program Memory Type: FLASH
• Eeprom Size: 256 x 8
• Ram Size: 768 x 8
• Voltage - Supply (vcc/vdd): 4.2 V ~ 5.5 V
• Data Converters: A/D 13x10b
• Oscillator Type: Internal
• Operating Temperature: -40°C ~ 85°C
• Package / Case: 44-TQFP, 44-VQFP
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

PIC18F2XXX/4XXX FAMILY
4.0
4.1
Code memory is accessed, one byte at a time, via the
4-bit command, ‘1001’ (Table Read, post-increment).
The contents of memory pointed to by the Table Pointer
(TBLPTRU:TBLPTRH:TBLPTRL) are serially output on
PGD.
TABLE 4-1:
FIGURE 4-1:
DS39622L-page 24
Step 1: Set Table Pointer.
Step 2: Read memory and then shift out on PGD, LSb to MSb.
PGC
Command
PGD
0000
0000
0000
0000
0000
0000
1001
4-Bit
READING THE DEVICE
Read Code Memory, ID Locations
and Configuration Bits
1
1
2
0E <Addr[21:16]>
6E F8
0E <Addr[15:8]>
6E F7
0E <Addr[7:0]>
6E F6
00 00
0
READ CODE MEMORY SEQUENCE
3
0
Data Payload
TABLE READ POST-INCREMENT INSTRUCTION TIMING (1001)
4
1
P5
PGD = Input
1
2
3
MOVLW Addr[21:16]
MOVWF TBLPTRU
MOVLW <Addr[15:8]>
MOVWF TBLPTRH
MOVLW <Addr[7:0]>
MOVWF TBLPTRL
TBLRD *+
4
5
6
7
8
P6
The 4-bit command is shifted in, LSb first. The read is
executed during the next 8 clocks, then shifted out on
PGD during the last 8 clocks, LSb to MSb. A delay of
P6 must be introduced after the falling edge of the 8th
PGC of the operand to allow PGD to transition from an
input to an output. During this time, PGC must be held
low (see
the Table Pointer by one, pointing to the next byte in
code memory for the next read.
This technique will work to read any memory in the
000000h to 3FFFFFh address space, so it also applies
to the reading of the ID and Configuration registers.
9
LSb
P14
10
1
11
Core Instruction
2
PGD = Output
Figure
12
Shift Data Out
3
13
4
4-1). This operation also increments
14
5
15
6
 2010 Microchip Technology Inc.
16
MSb
P5A
Fetch Next 4-Bit Command
1
PGD = Input
n
2
n
3
n
4
n