USB2228 SMSC Corporation, USB2228 Datasheet - Page 16

• Manufacturer Part Number: USB2228
• Description: (USB2227 / USB2228) 4th Generation USB2.0 Flash Media Controller
• Manufacturer: SMSC Corporation

Revision 1.91 (10-13-06)
SYMBOL
MA[15:3]
MD[7:0]
XTAL1/
XTAL2
CLKIN
128-PIN
VTQFP
102
103
128
127
126
125
124
123
122
121
120
119
12
11
10
9
8
7
6
5
4
2
1
124-PIN
DQFN
A51
B49
B60
A64
B59
A63
B58
A62
B57
A61
A60
B56
B6
A6
B5
A5
A4
B4
A3
B3
A2
A1
B1
MEMORY/IO INTERFACE
4th Generation USB2.0 Flash Media Controller with Integrated Card Power FETs
BUFFER
I/O8PU
OCLKx
ICLKx
TYPE
O8
DATASHEET
16
Crystal Input/External Clock Input:
24Mhz Crystal or external clock input.
This pin can be connected to one terminal of the crystal
or can be connected to an external 24Mhz clock when
a crystal is not used.
Note:
Crystal Output:
24Mhz Crystal
This is the other terminal of the crystal, or left open when
an external clock source is used to drive XTAL1/CLKIN.
It may not be used to drive any external circuitry other
than the crystal circuit.
Memory Data Bus:
When ROMEN bit of GPIO_IN1 register = 0, these
signals are used to transfer data between the internal
CPU and the external program memory.
These pins have internally controlled weak pull-up
resistors.
Memory Address Bus:
These signals address memory locations within the
external memory.
The ‘MA[2:0] pins will be sampled while
nRESET is asserted, and the value will be
latched upon nRESET negation. This will
determine the clock source and value.
DESCRIPTION
SMSC USB2227/USB2228
Datasheet