PIC18F4550-I/PT Microchip Technology Inc., PIC18F4550-I/PT Datasheet - Page 190

• Manufacturer Part Number: PIC18F4550-I/PT
• Description: 44 PIN, 32 KB FLASH, 2048 RAM, FS-USB 2.0
• Manufacturer: Microchip Technology Inc.

Specifications of PIC18F4550-I/PT

• A/d Inputs: 13-Channel, 10-Bit
• Comparators: 2
• Cpu Speed: 12 MIPS
• Eeprom Memory: 256 Bytes
• Input Output: 34
• Interface: I2C/SPI/UART/USART/USB
• Memory Type: Flash
• Number Of Bits: 8
• Package Type: 44-pin TQFP
• Programmable Memory: 32K Bytes
• Ram Size: 2K Bytes
• Speed: 48 MHz
• Timers: 1-8-bit, 3-16-bit
• Voltage, Range: 2-5.5 V
• Lead Free Status / Rohs Status: RoHS Compliant part Electrostatic Device

PIC18F2455/2550/4455/4550
REGISTER 18-2:
18.1.2
The SPP has four control outputs:
• Two separate clock outputs (CK1SPP and
• Output enable (OESPP)
• Chip select (CSSPP)
Together, they allow for several different configurations
for controlling the flow of data to slave devices. When
all control outputs are used, the three main options are:
• CLK1 clocks endpoint address information while
• CLK1 clocks write operations while CLK2 clocks
• CLK1 clocks Odd address data while CLK2 clocks
Additional control options are derived by disabling the
CK1SPP and CSSPP outputs. These are enabled or
disabled with the CLK1EN and CSEN bits, respectively,
located in Register 18-2.
DS39632C-page 188
bit 7
Legend:
R = Readable bit
-n = Value at POR
bit 7-6
bit 5
bit 4
bit 3-0
CK2SPP)
CLK2 clocks data
reads
Even address data
CLKCFG1
R/W-0
CLOCKING DATA
CLKCFG1:CLKCFG0: SPP Clock Configuration bits
1x = CLK1 toggles on read or write of an Odd endpoint address;
01 = CLK1 toggles on write; CLK2 toggles on read
00 = CLK1 toggles only on endpoint address write; CLK2 toggles on data read or write
CSEN: SPP Chip Select Pin Enable bit
1 = RB4 pin is controlled by the SPP module and functions as SPP CS output
0 = RB4 functions as a digital I/O port
CLK1EN: SPP CLK1 Pin Enable bit
1 = RE0 pin is controlled by the SPP module and functions as SPP CLK1 output
0 = RE0 functions as a digital I/O port
WS3:WS0: SPP Wait States bits
1111 = 30 additional wait states
1110 = 28 additional wait states
•
•
0001 = 2 additional wait states
0000 = 0 additional wait states
CLKCFG0
R/W-0
SPPCFG: SPP CONFIGURATION REGISTER
CLK2 toggles on read or write of an Even endpoint address
W = Writable bit
‘1’ = Bit is set
R/W-0
CSEN
•
•
CLK1EN
R/W-0
Preliminary
U = Unimplemented bit, read as ‘0’
‘0’ = Bit is cleared
R/W-0
WS3
18.1.3
The SPP is designed with the capability of adding wait
states to read and write operations. This allows access
to parallel devices that require extra time for access.
Wait state clocking is based on the data source clock.
If the SPP is configured to operate as a USB endpoint,
then wait states are based on the USB clock. Likewise,
if the SPP is configured to operate from the micro-
controller, then wait states are based on the instruction
rate (F
The WS3:WS0 bits set the wait states used by the SPP,
with a range of no wait states to 30 wait states, in multi-
ples of two. The wait states are added symmetrically to
all transactions, with one-half added following each of the
two clock cycles normally required for the transaction.
Figure 18-3 and Figure 18-4 show signalling examples
with 4 wait states added to each transaction.
18.1.4
The SPP data lines (SPP<7:0>) are equipped with
internal pull-ups for applications that may leave the port
in a high-impedance condition. The pull-ups are
enabled using the control bit, RDPU (PORTE<7>).
OSC
/4).
WAIT STATES
SPP PULL-UPS
R/W-0
WS2
© 2006 Microchip Technology Inc.
x = Bit is unknown
R/W-0
WS1
R/W-0
WS0
bit 0