MCM63L836A
MCM63L918A
13
MOTOROLA FAST SRAM
SLEEP MODE
This device is equipped with an optional sleep or low
power mode. The sleep mode pin is asynchronous and
active high. During normal operation, the ZZ pin is pulled low.
When ZZ is pulled high, the chip will enter sleep mode where
the device will meet the lowest possible power conditions.
The Sleep Mode Timing diagram shows the following modes
of operation: Normal Operation, No Read/Write Allowed, and
Sleep Mode.
Normal Operation
All inputs must meet setup and hold times prior to sleep
and tZZR nanoseconds after recovering from sleep. Clock
(CK) must also meet cycle high and low times during these
periods. Two cycles prior to sleep, initiation of either a read or
write operation is not allowed.
No Read/Write Allowed
During the period of time just prior to sleep and during
recovery from sleep, the assertion of any write or read signal
is not allowed. If a write or read operation occurs during
these periods, the memory array may be corrupted. Validity
of data out from the RAM can not be guaranteed immediately
after ZZ is asserted (prior to being in sleep). During sleep
mode recovery, the output impedance must be given
additional time above and beyond tZZR in order to match
desired impedance (see explanation in
Output Impedance
Circuitry
paragraph).
Sleep Mode
The RAM automatically deselects itself. The RAM discon-
nects its internal clock buffer. The external clock may con-
tinue to run without impacting the RAMs sleep current (IZZ).
All outputs will remain in a High–Z state while in sleep mode.
All inputs are allowed to toggle. The RAM will not be
selected, and perform any reads or writes.
SERIAL BOUNDARY SCAN TEST ACCESS PORT OPERATION
OVERVIEW
The serial boundary scan test access port (TAP) on this
RAM is designed to operate in a manner consistent with
IEEE Standard 1149.1–1990 (commonly referred to as
JTAG), but does not implement all of the functions required
for IEEE 1149.1 compliance. Certain functions have been
modified or eliminated because their implementation places
extra delays in the RAMs critical speed path. Nevertheless,
the RAM supports the standard TAP controller architecture.
The TAP controller is the state machine that controls the TAP
operation and can be expected to function in a manner that
does not conflict with the operation of devices with IEEE
1149.1 compliant TAPs. The TAP operates using conven-
tional JEDEC Standard 8–1B low voltage (3.3 V) TTL/CMOS
logic level signaling.
DISABLING THE TEST ACCESS PORT
It is possible to use this device without utilizing the TAP. To
disable the TAP controller without interfering with normal
operation of the device, TCK must be tied to VSS to preclude
mid–level inputs. TDI and TMS are designed so an undriven
input will produce a response identical to the application of a
logic 1, and may be left unconnected. But they may also be
tied to VDD through a 1 k resistor. TDO should be left uncon-
nected.
TAP DC OPERATING CHARACTERISTICS
(3.0 V
≤
VDD
≤
3.6 V, 0
°
C
≤
TA
≤
70
°
C, Unless Otherwise Noted)
Parameter
Symbol
Min
Max
Unit
Notes
Logic Input Logic High
VIH1
VIL1
Ilkg
VOL1
VOH1
VOL2
VOH2
1.2
VDD + 0.3
0.4
±
5
0.2
V
Logic Input Logic Low
–0.3
V
μ
A
V
Logic Input Leakage Current
—
1
CMOS Output Logic Low
—
2
CMOS Output Logic High
VDD – 0.2
—
—
V
3
TTL Output Logic Low
0.4
V
4
TTL Output Logic High
NOTES:
1. 0 V
≤
Vin
≤
VDD for all logic input pins.
2. IOL1
≤
100
μ
A @ VOL = 0.2 V. Sampled, not 100% tested.
3. |IOH1|
≤
100
μ
A @ VDDQ – 0.2 V. Sampled, not 100% tested.
4. IOL2
≤
8 mA @ VOL = 0.4 V.
5. |IOH2|
≤
8 mA @ VOH = 2.4 V.
2.4
—
V
5