XE8805 SEMTECH [Semtech Corporation], XE8805 Datasheet - Page 66

• Manufacturer Part Number: XE8805
• Description: Data Acquisition MCU
• Manufacturer: SEMTECH [Semtech Corporation]

12.1 Features
• Input / output / analog port, 8 bits wide
• Each bit can be set individually for input or output
• Each bit can be set individually for open-drain or push-pull
• Each bit can be set individually for pull-up or not (for input or open-drain mode)
• In open-drain mode, pull-up is not active when corresponding pad is set to zero
• The 8 pads can be connected by pairs to four internal analog lines (4 line analog bus)
• Two internal freq. (cpuck and 32 kHz) can be output on PB[2] and PB[3]
Product dependant:
• Two PWM signal can be output on pads PB[0] and PB[1]
• The synchronous serial interface (USRT) uses pads PB[5], PB[4]
• The UART interface uses pads PB[6] and PB[7] for Tx and Rx
12.2 Overview
Port B is a multi-purpose 8 bit Input/output port. In addition to digital functions, all pins can be used for analog
signals. All port terminals can be selected by pairs as digital input or output or as analog to share one of four
possible analog lines.
12.3 Register map
© Semtech 2006
Pos.
Pos.
Pos.
Pos.
Pos.
Pos.
7 – 0
7 – 0
7 – 0
7 – 0
7 – 4
7 –0
3
2
1
0
PBOut[7-0]
PBDir [7-0]
PBIn[7-0]
PBOpen[7-0]
PBPullup[7]
--
PBAna [3]
PBAna [2]
PBAna [1]
PBAna [0]
RegPBPullup
RegPBOpen
RegPBOut
RegPBAna
RegPBDir
RegPBIn
r w
r w
r w
r w
r w
r
r w
r w
r w
r w
rw
rw
rw
rw
rw
rw
0 resetpconf
0 resetpconf
0 resetpconf
0 resetpconf
0000
0 resetpconf
0 resetpconf
0 resetpconf
0 resetpconf
reset
reset
reset
reset
reset
reset
Table 12-5: RegPBPullup
Table 12-4: RegPBOpen
Table 12-6: RegPBAna
Table 12-1: RegPBOut
Table 12-3: RegPBDir
Table 12-2: RegPBIn
Pad PB[7-0] output value
Pad PB[7-0] input status
Pad PB[7-0] direction (0=input)
Pad PB[7-0] open drain (1 = open
drain)
Pull-up for pad PB[7-0] (1=active)
Unused
Set PB[7:6] in analog mode
Set PB[5:4] in analog mode
Set PB[3:2] in analog mode
Set PB[1:0] in analog mode
description in digital mode
description in digital mode
description in digital mode
description in digital mode
description in digital mode
description in digital mode
12-2
Analog bus selection for pad PB[7-0]
Unused
Analog bus selection for pad PB[7-0]
Unused
Connect pad PB[7-0] on selected ana
bus
Unused
Set PB[7:6] in analog mode
Set PB[5:4] in analog mode
Set PB[3:2] in analog mode
Set PB[1:0] in analog mode
description in analog mode
description in analog mode
description in analog mode
description in analog mode
description in analog mode
description in analog mode
XE8805/05A
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