Daughter Board Stack; Daughter Board Wait# Output - Renesas SH7727 General Information Manual

R0P7727TH003TRKE General Information Manual

9.3 Daughter Board Stack

A maximum of 2 daughter boards can be stacked. When multiple daughter boards are stacked, care should
be taken for electric capacity. Figure 9.2 shows an example of daughter board stacks.
T-Engine Board
Daughter Board
Daughter Board

9.4 Daughter Board WAIT# Output

T-Engine is provided with an /WAIT input pin on the expansion slot for /WAIT input to the daughter board.
When /WAIT is output from the daughter board, open collector output must take place to prevent a collision of
/WAIT output when multiple daughter boards are stacked.
In addition, the /WAIT pin on T-Engine is subject to pull-up with 680 ohms. Figure 9.3 shows an /WAIT pin
structure on the expansion slot.
SH7727
Figure 9.2 Daughter Board Stack
T-Engine board side
3.3V
Expansion
680Ω
Buffer
Figure 9.3 Expansion Slot /WAIT Pin Structure
Expansion slot: 24-5603-14-0101-861+
Expansion slot: 14-5603-14-0101-861+
Expansion slot: 24-5603-14-0101-861+
Expansion slot: 14-5603-14-0101-861+
Expansion slot: 24-5603-14-0101-861+
Daughter board side
Expansion
slot
slot
Open collector output
100
Daughter Board Design Guide
Extended device
/WAIT output
(Active Low)