Rainbow Electronics DS28DG02 - Manual (Page 9)

DS28DG02: 2kb SPI EEPROM with PIO, RTC, Reset, Battery Monitor, and Watchdog
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Power-On Default for PIO Read Inversion (PIO8 to PIO11), PIO Output Type and Output Mode
ADDR b7 b6 b5 b4 b3 b2 b1 b0
10Fh POTM POT3 POT2 POT1 PIM11 PIM10 PIM9 PIM8
There is general read and write access to this address. Factory default: 80h. The contents of this register are
automatically transferred to address 125h when the device powers up.
BIT DESCRIPTION BIT(S) DEFINITION
PIMn: PIO Power-On
Default Read-Inversion
b0 to b3
Power-on default state of the read-inversion bit of PIO8 to PIO11. PIM8
applies to PIO8, etc.
Legend
: 0 Î no inversion; 1 Î inversion
POT1: Power-On
Default Output Type
b4
Power-on default output type of PIO0 to PIO3;
Legend
: 0 Î push-pull; 1 Î open drain
POT2: Power-On
Default Output Type
b5
Power-on default output type of PIO4 to PIO7;
Legend
: 0 Î push-pull; 1 Î open drain
POT3: Power-On
Default Output Type
b6
Power-on default output type of PIO8 to PIO11;
Legend
: 0 Î push-pull; 1 Î open drain
POTM: Power-On
Default Output Mode
b7
Power-on default output mode of PIO0 to PIO11;
Legend
: 0 Î low-current, simultaneous switching; 1 Î high-current,
sequential switching
Unique Registration Number (118h to 11Fh)
Each DS28DG02 has a unique registration number that is 64 bits long, as shown in Figure 3. The registration
number begins with the family code at address 118h followed by the 48-bit serial number (LS-byte at the lower
address) and ends at address 11Fh with the Cyclic Redundancy Check (CRC) of the first 56 bits. This CRC is
generated using the a polynomial X
8 + X 5 + X 4 + 1. Additional information about CRCs is available in Application
Note 27 .
Figure 3. 64-Bit Registration Number
MSB LSB
8-Bit CRC Code 48-Bit Serial Number 8-Bit Family Code (70h)
MSB LSB MSB LSB MSB LSB
PIO Output State
ADDR b7 b6 b5 b4 b3 b2 b1 b0
120h OV7 OV6 OV5 OV4 OV3 OV2 OV1 OV0
121h X X X X OV11 OV10 OV9 OV8
There is general read and write access to these addresses. These registers are automatically loaded with data
from address 10Ah/10Bh when the device powers up.
BIT DESCRIPTION BIT(S) DEFINITION
OVn: PIO Output State —
Output state of PIO0 to PIO11. OV0 applies to PIO0, etc.
Legend
: 0 Î LOW; 1 Î HIGH if PIO direction is output
X: (Not Assigned) — Reserved for future use.