EZ80F915050MOD Datasheet, PDF (18/34 Pages) Zilog, Inc. – eZ80F91 Module compact, high-performance Ethernet module

eZ80F915050MOD
eZ80F91 Module Product Specification
12
Onboard Component Description
Logic-Level I/Os
The I/O connector features 32 general-purpose 3.3 V CMOS I/O pins that can be
used as outputs or inputs interfacing to external logic. All I/Os are 5 V tolerant.
Some of the General-Purpose I/O pins support dual mode functions (SPI, Timer I/O,
UARTs and bit I/O with edge- or level-triggered interrupt functions on each pin). For
more information on eZ80F91 dual modes, please refer to the eZ80F91 Product
Specification (PS0192).
Onboard Battery Backup
An onboard Panasonic VL-1220-1VC 3V Lithium battery powers the 32kHz Real-
Time Clock when external power is removed. The battery is charged through
diode CR1 and resistor R28 when external power is applied to the board.
Ethernet PHY and RJ45 Connector
The eZ80F91 Ethernet Module contains Advanced Micro Devices’ Am79C874
Media-Independent Interface (MII) and a HALO RJ45 with integrated magnetics
(transformer and common-mode chokes) and two LED indicators.
The MII enables different modes of Ethernet communication, configurable by
resistors R19, R21, R23, and R24. The eZ80F91 Ethernet Module is shipped with
all four resistors installed. Table 4, which lists the available resistor settings, is
excerpted from the Am79C874 data sheet published by AMD.
Table 4. eZ80F91 Ethernet Module MII Resistor Configuration
R24
ANEG
IN
R19
R23
R21
Full-
(Tech[2]) (Tech[1]) (Tech[0]) Speed Duplex
IN
IN
IN
Yes¹ Yes¹
ANEG-EN Capabilities
No All
ANEG
Disabled
IN
IN
IN
OUT No
No
No 10HD
Disabled
IN
IN
OUT
IN
No
No
No 100HD
Disabled
Notes:
1. MII Register 0 (Speed and Duplex Bits) must be set by a MAC to achieve a link.
2. When autonegotiation is enabled, these bits can be written but will be ignored by PHY.
3. The advertised abilities of MII Register 4 cannot exceed the abilities of MII Register 1. Autonegotiation should
always be enabled.
PS019310-0904
PRELIMINARY
Onboard Component Description