USB2250 SMSC Corporation, USB2250 Datasheet - Page 19

• Manufacturer Part Number: USB2250
• Description: Ultra Fast USB 2.0 Multi-Format Flash Media Controller
• Manufacturer: SMSC Corporation

Ultra Fast USB 2.0 Multi-Format Flash Media Controller
Datasheet
SMSC USB2250/51/59
Memory Data
Bus
Memory
Address Bus
Memory
Address Bus
Memory
Address Bus
Memory Write
Strobe
Memory Read
Strobe
NAME
Table 5.1 USB2250/51/59 128-Pin VTQFP Pin Descriptions (continued)
MA1[1:0] /
SEL1[1:0]
SYMBOL
MA[15:2]
MD[7:0]
nMWR
nMRD
MA16
CLK_
128-PIN
VTQFP
107
113
109
106
108
110
112
114
116
115
111
33
29
30
31
34
35
36
37
28
24
25
27
2
4
1
3
MEMORY / IO INTERFACE
DATASHEET
BUFFER
I/O12PD
TYPE
I/O12
O12
O12
O12
O12
O12
19
DESCRIPTION
These signals are used to transfer data between
the internal CPU and the external program
memory.
Note:
These signals address memory locations within
the external memory. MA16 is a bit generated by
the ROM Mapper.
These signals address memory locations within
the external memory.
Note: USB2259 requires that MA2 be tied to
MA[1:0]: These signals address memory locations
within the external memory.
CLK_SEL[1:0]: During nRESET assertion, these
pins will select the operating frequency of the
external clock, and the corresponding weak pull-
down resistors are enabled. When nRESET is
negated, the value on these pins will be internal
latched and these pins will revert to MA[1:0]
functionality; the internal pull-downs will be
disabled.
CLK_SEL[1:0] = '00'. 24MHz
CLK_SEL[1:0] = '01'. RESERVED
CLK_SEL[1:0] = '10'. RESERVED
CLK_SEL[1:0] = '11'. 48MHz
Note:
If the latched value is '0', then the corresponding
MA pin will function identically to the MA[15:3]
pins at all times (other than during nRESET
assertion).
Program Memory Write; active low
Program Memory Read; active low
3.3V via a 10K resistor.
These pins have internal weak pull-up
resistors that are controlled by the
MD_PU_DIS bit of the
PWR_MGMT_CTL1 register.
If the latched value is '1', then the
corresponding MA pin is tri-stated when
the chip is in the powerdown state.
Revision 2.6 (05-08-08)