PIC18F452-I/ML Microchip Technology, PIC18F452-I/ML Datasheet - Page 20

• Manufacturer Part Number: PIC18F452-I/ML
• Description: IC MCU FLASH 16KX16 A/D 44QFN
• Manufacturer: Microchip Technology
• Series: PIC® 18Fr

Specifications of PIC18F452-I/ML

• Core Size: 8-Bit
• Program Memory Size: 32KB (16K x 16)
• Core Processor: PIC
• Speed: 40MHz
• Connectivity: I²C, SPI, UART/USART
• Peripherals: Brown-out Detect/Reset, LVD, POR, PWM, WDT
• Number Of I /o: 34
• Program Memory Type: FLASH
• Eeprom Size: 256 x 8
• Ram Size: 1.5K x 8
• Voltage - Supply (vcc/vdd): 4.2 V ~ 5.5 V
• Data Converters: A/D 8x10b
• Oscillator Type: External
• Operating Temperature: -40°C ~ 85°C
• Package / Case: 44-QFN
• Controller Family/series: PIC18
• No. Of I/o's: 34
• Eeprom Memory Size: 256Byte
• Ram Memory Size: 1.5KB
• Cpu Speed: 40MHz
• No. Of Timers: 4
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• For Use With: XLT44QFN2 - SOCKET TRAN ICE 44QFN/40DIP444-1001 - DEMO BOARD FOR PICMICRO MCU
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant, Lead free / RoHS Compliant

PIC18FXX2/XX8
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 loaded into the
Table Latch and then serially output on SDATA.
TABLE 4-1:
FIGURE 4-1:
DS39576C-page 20
Step 1: Set Table Pointer.
Step 2: Read memory into Table Latch and then shift out on SDATA, LSb to MSb.
SCLK
SDATA
Command
0000
0000
0000
0000
0000
0000
1001
4-Bit
READING THE DEVICE
Read Code Memory, ID Locations,
and Configuration Bits
1
1
0E <Addr[21:16]>
6E F8
0E <Addr[15:8]>
6E F7
0E <Addr[7:0]>
6E F6
00 00
READ CODE MEMORY SEQUENCE
2
0
3
Data Payload
TABLE READ POST-INCREMENT INSTRUCTION TIMING (1001)
0
4
1
P5
SDATA = 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
SDATA during the last 8 clocks, LSb to MSb. A delay of
P6 must be introduced after the falling edge of the 8th
SCLK of the operand to allow SDATA to transition from
an input to an output. During this time, SCLK must be
held low (see Table 4-1). This operation also
increments the Table Pointer 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
Core Instruction
11
2
SDATA = Output
12
Shift Data Out
3
13
4
14
5
15
 2010 Microchip Technology Inc.
6
16
MSb
P5A
Fetch Next 4-bit Command
1
SDATA = Input
n
2
n
3
n
4
n