71m6403 Teridian Semiconductor Corporation, 71m6403 Datasheet - Page 35

• Manufacturer Part Number: 71m6403
• Description: Electronic Trip Unit
• Manufacturer: Teridian Semiconductor Corporation

DIO Ports
The 71M6402 includes up to 22 pins of general purpose digital I/O. 18 of these pins are dual function and can alternatively be
used as LCD drivers. Figure 6 shows a block diagram of the DIO section.
On reset or power-up, all DIO pins are inputs until they are configured for the desired direction. The pins are configured and con-
trolled by the DIO and DIO_DIR registers (SFRs) and by the five bits of the I/O register LCD_NUM (0x2020[4:0]). See the
description for LCD_NUM in the I/O RAM Section for a table listing the available segment pins versus DIO pins, depending on
the selection for LCD_NUM. Generally, increasing the value for LCD_NUM will configure an increasing number of general
purpose pins to be LCD segment pins, starting at the higher pin numbers.
Each pin declared as DIO can be configured independently as an input or output with the bits of the DIO_DIRn registers. Table
51 lists the direction registers and configurability associated with each group of DIO pins. Table 52 shows the configuration for a
DIO pin through its associated bit in its DIO_DIR register.
Page: 35 of 75
DIO Pin Group
DIO_0…DIO_3
DIO 4…DIO7
DIO 8…DIO11
DIO 12…DIO15
DIO 16…DIO21
Type
DIO only
Multi-use
Multi-use
Multi-use
Multi-use
Table 51: Direction Registers and Internal Resources for DIO Pin Groups
MPU
Port
P0
P0
P1
P1
P2
DIO Pin Function
Figure 6: DIO Ports Block Diagram
LCD_EN
LCD_FS
LCD_MODE
LCD_NUM
LCD_MODE
LCD_CLK
DIO_EEX
FAULT_PULSE
STROBE
DIO_IN
DIO_OUT
LCD_NUM
DIO_GP
Direction
LCD DISPLAY
Register
DIGITAL I/O
Name
DRIVER
©
DIR0
DIR1
DIR2
Table 52: DIO_DIR Control Bit
2006 TERIDIAN Semiconductor Corporation
On-Chip Resources
0xA2 [3:0]
0xA2 [7:4]
0x91 [3:0]
Direction
0xA1[5:0]
Location
0x91[7:4]
Register
(SFR)
input
COM0..3
SEG6/SRDY
SEG20..23
DIO_0..3
SEG0..2, SEG3/SCLK,
SEG4/SSDATA,
SEG5/SFR, SEG7..19
SEG24/DIO4 ..
SEG27/DIO7
SEG28/DIO8 ..
SEG31/DIO11
SEG32/DIO12 ..
SEG41/DIO21
0
DIO_DIR bit
Register
Name
Data
P0
P1
P2
output
Electronic Trip Unit
1
0x80 [3:0]
0x80 [7:4]
0x90 [3:0]
0xA0[5:0]
Location
0x90[7:4]
Data Re-
gister
(SFR)
Internal resources
selectable when
configured as DIO
Yes
Yes
No
No
Yes
71M6403
SEPTEMBER 2006
REV 1.0