Programming Model

Programming Model

This section defines the programming model for the control and status registers (CSR) in the PCCchip2. The base address of the CSR is $FFF42000. The PCCchip2 control and status registers can be accessed as bytes (8 bits), two-bytes (16 bits), or four-bytes(32 bits). The possible operations for each bit in the CSR are as follows:

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RThis bit is a read only status bit.

R/W This bit is readable and writable.

W/AC This bit can be set and it is automatically cleared.

This bit can also be read.

CWriting a one to this bit clears this bit or another bit. This bit reads zero.

SWriting a one to this bit sets this bit or another bit. This bit reads zero.

0This bit is read only. It always reads as 0.

The possible states of the bits after local and power-up reset are as defined below.

PThe bit is affected by power-up reset.

LThe bit is affected by local reset.

XThe bit is not affected by reset.

VThe effect of reset on this bit is variable.

0The bit is always 0.

1The bit is always 1.

A summary of the PCCchip2 CSR is shown in Table 6-2.

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Motorola MVME1X7P manual Programming Model, Summary of the PCCchip2 CSR is shown in Table