Texas Instruments SM320F2812-HT specifications Signal Descriptions, Center Description HFG

SM320F2812-HT

SGUS062A –JUNE 2009 –REVISED APRIL 2010www.ti.com

Table 2-3. Signal Descriptions (1)

(continued)

PIN NO.

DIE PAD

DIE PAD

DIE PAD

I/O/Z (2)

PU/PD (3)

NAME

172-PIN

X-CENTER

Y-CENTER

DESCRIPTION

HFG

NO.

(μm)

(μm)

Microprocessor/Microcomputer Mode

Select. Switches between microprocessor

and microcomputer mode. When high,

Zone 7 is enabled on the external interface.

When low, Zone 7 is disabled from the

XMP/MC

17

23

2308.2

42.6

I

PD

external interface and on-chip boot ROM

may be accessed instead. This signal is

latched into the XINTCNF2 register on a

reset and the user can modify this bit in

software. The state of the XMP/MC pin is

ignored after reset.

External Hold Request.

when

XHOLD,

active (low), requests the XINTF to release

the external bus and place all buses and

XHOLD

155

174

42.6

2157.6

I

PU

strobes into a high-impedance state. The

XINTF releases the bus when any current

access is complete and there are no

pending accesses on the XINTF.

External Hold Acknowledge.

is

XHOLDA

driven active (low) when the XINTF has

granted a XHOLD request. All XINTF buses

and strobe signals are in a high-impedance

XHOLDA

80

93

5361.5

4137.4

O/Z

–

state. XHOLDA is released when the

XHOLD signal is released. External devices

should only drive the external bus when

XHOLDA is active (low).

XINTF Zone 0 and Zone 1 Chip Select.

XZCS0AND1

is active (low) when an

XZCS0AND1

43

50

5148.5

42.6

O/Z

–

access to the XINTF Zone 0 or Zone 1 is

performed.

XINTF Zone 2 Chip Select.

is active

XZCS2

XZCS2

86

100

5361.5

4844.2

O/Z

–

(low) when an access to the XINTF Zone 2

is performed.

XINTF Zone 6 and Zone 7 Chip Select.

XZCS6AND7

is active (low) when an

XZCS6AND7

130

146

42.6

4888.6

O/Z

–

access to the XINTF Zone 6 or Zone 7 is

performed.

Write Enable. Active-low write strobe. The

write strobe waveform is specified, per zone

XWE

82

95

5361.5

4347.5

O/Z

–

basis, by the Lead, Active, and Trail periods

in the XTIMINGx registers.

Read Enable. Active-low read strobe. The

read strobe waveform is specified, per zone

basis, by the Lead, Active, and Trail periods

XRD

41

48

4900.6

42.6

O/Z

–

in the XTIMINGx registers.

NOTE: The XRD and XWE signals are

mutually exclusive.

Read Not Write Strobe. Normally held high.

When low, XR/W

indicates write cycle is

XR/W

50

57

5361.5

755.0

O/Z

–

active; when high, XR/W indicates read

cycle is active.

Ready Signal. Indicates peripheral is ready

to complete the access when asserted to 1.

XREADY

157

176

42.6

1972.4

I

PU

XREADY can be configured to be a

synchronous or an asynchronous input.

See the timing diagrams for more details.

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