MCP25020-E Datasheet, PDF (34/66 Pages) Microchip Technology – CAN I/O Expander Family

MCP2502X/5X
REGISTER 5-6: OPTREG1 REGISTER
R/W-1 R/W-1 R/W-1 R/W-1
U-0
R/W-0 R/W-0 R/W-0
GPPU CLKEN CLKPS1 CLKPS0
—
CMREQ AQT1
AQT0
bit 7
bit 0
bit 7
bit 6
bit 5-4
bit 3
bit 2
bit 1-0
GPPU: Weak pull-up enabled
1 = Weak pull-ups disabled
0 = Weak pull-ups enabled (GP7:GP0)
CLKEN:
1 = Clock Out Function disabled
0 = Clock Out Function enabled
CLKPS1:CLKPS0: CLKOUT Prescaler bits
00 = FOSC/1
01 = FOSC/2
10 = FOSC/4
11 = FOSC/8
Reserved:
CMREQ: Requests mode of operation (allows mode changes via the CAN bus)
1 = Requests Listen-only mode
0 = Requests Normal mode *
* CMREQ must be cleared as default to avoid device entering Listen-only mode on first “Input”
message.
AQT1:AQT0: Analog Acquisition Time bits
00 = 64TOSC
01 = 2•(64TOSC)
10 = 4•(64TOSC)
11 = 8•(64TOSC)
(e.g., AQT1:AQT0 => 00 => 2.56 µs for a 25 MHz FOSC)
Legend:
R = Readable bit
- n = Value at POR
W = Writable bit
‘1’ = Bit is set
U = Unimplemented bit, read as ‘0’
‘0’ = Bit is cleared x = Bit is unknown
DS21664D-page 34
© 2007 Microchip Technology Inc.