User’s Manual
M68HC12A4EVB Evaluation Board — Rev. 1
80
Hardware Reference
MOTOROLA
Hardware Reference
W11 ROM and RAM Chip Select (CS)
1–2
2–3
Connects an MCU chip select to the devices installed in the ROM sockets
Connects an MCU chip select to the devices installed in the RAM sockets
Default: CSP0 is the ROM chip select.
CSD is the RAM chip select.
W12
(1)
RAM Pin Assignment — Pin 30 of 32-pin package
or pin 28 of 28-pin package
1–2
3–4
5–6
Pin is connected to MCU address line A17 for narrow modes.
Pin is connected to MCU address line A18 for wide modes.
Pin is connected to V
DD
for 28-pin devices.
W13
(1)
RAM Pin Assignment — Pin 28 of 32-pin package
or pin 26 of 28-pin package
1–2
3–4
5–6
Pin is connected to MCU address line A13 for narrow modes.
Pin is connected to MCU address line A14 for wide modes.
Pin is connected to V
DD
for the device’s chip enable (CE2).
W14 SCI Port Assignment to Terminal Interface
1–2
2–3
SCI port 0 serves as the D-Bug12 terminal interface.
SCI port 1 serves as the D-Bug12 terminal interface.
Table 4-1. Jumper-Selectable Functions (Sheet 2 of 4)
Diagram
Setting
Description
(1)
W12 and W13 together select the type of RAM installed.
(2)
W22, W24, W29, W32, W33, and W36 together select the type of ROM installed.
(3)
W30, W34, and W42 together determine the MCU’s mode of operation.
3
2
1
CS0
CS1
CS2
CS3
CSD
CSP0
CSP1
ROM
RAM
5
3
1
6
4
2
5
3
1
6
4
2
1
2
3
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Freescale Semiconductor, Inc.
For More Information On This Product,
Go to: www.freescale.com
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