EZ80F91MCU ZILOG [Zilog, Inc.], EZ80F91MCU Datasheet - Page 34

• Manufacturer Part Number: EZ80F91MCU
• Description: eZ80Acclaim-TM Flash Microcontrollers
• Manufacturer: ZILOG [Zilog, Inc.]

Table 2. Pin Identification on the eZ80F91 Device (Continued)
PS019209-0504
LQFP
Pin #
56
57
58
59
60
61
62
Note: *PHY represents the physical layer of the OSI model.
BGA
Pin#
J6
M7
L7
K7
H6
M8
L8
Symbol
NMI
BUSREQ
BUSACK
V
V
RTC_X
RTC_X
DD
SS
IN
OUT
Function
Nonmaskable
Interrupt
Bus Request
Bus
Acknowledge
Power Supply
Ground
Real-Time
Clock Crystal
Input
Real-Time
Clock Crystal
Output
P R E L I M I N A R Y
Signal Direction
Schmitt-trigger input,
Active Low
Schmitt-trigger input,
Active Low
Output, Active Low
Input
Bidirectional
Description
The NMI input is a higher priority
input than the maskable
interrupts. It is always recognized
at the end of an instruction,
regardless of the state of the
interrupt enable control bits. This
input includes a Schmitt trigger to
allow RC rise times.
External devices can request the
eZ80F91 device to release the
memory interface bus for their
use, by driving this pin Low.
The eZ80F91 device responds to
a Low on BUSREQ, by tristating
the address, data, and control
signals, and by driving the
BUSACK line Low. During bus
acknowledge cycles ADDR[23:0],
IORQ, and MREQ are inputs.
Power Supply.
Ground.
This pin is the input to the low-
power 32KHz crystal oscillator for
the Real-Time Clock.
This pin is the output from the
low-power 32KHz crystal
oscillator for the Real-Time Clock.
This pin is an input when the RTC
is configured to operate from 50/
60 Hz input clock signals and the
32 KHz crystal oscillator is
disabled.
Product Specification
Architectural Overview
eZ80F91 MCU
15