User`s guide

2.1 Conﬁguration Jumpers

Table 2–1 (Cont.) Conﬁguration Jumper Position Descriptions

Feature Jack/Jumper—Pins and Description

BOOT_OPTION J1—25/26 (CONF11) (eb164.4)

This jumper selects the image to be loaded into memory from

the system ﬂash ROM. With the jumper out (bit = 1), the ﬁrst

image (debug monitor) is loaded. With the jumper in (bit = 0),

alternate images can be loaded depending upon the value stored

in TOY RAM location 0x3F. The default position for this jumper is

out.

For system ROMs that contain a single image, the header is

optional. If the header does not exist, the entire 1MB system ROM

is loaded and executed at physical address zero.

For more information on the SROM header and boot images, refer

to Section B.8.

BC_RD_FAST J1—29/30 (CONF13) (eb164.4)

This jumper forces a Bcache read speed setting of 1 cycle faster

than nominal.

BC_RD_FAST Bcache Speed

In Make read speed 1 cycle faster

Out Nominal read speed (default)

Flash ROM write-

protect/write-

enable jumper

J14 (eb164.33)

Jumper Pins Function

1 to 2 Flash ROM write-protect

2 to 3 Flash ROM write-enable (default)

System Conﬁguration and Connectors 2–7