Datasheet

Microcontroller Interface

SGLS139B − October 2003 − Revised April 2004 TSB12LV32-EP

3 Microcontroller Interface

The microcontroller interface allows the local microcontroller/microprocessor to communicate with the internal

control and configuration registers (CFR), asynchronous transfer FIFO (ATF) and general receive FIFO

(GRF). All microcontroller reads/writes are initiated by the microcontroller. The microcontroller interface

supports read transactions from the CFR or GRF, and write transactions to the CFR or ATF.

The microcontroller interface can operate in byte (8 bit) or word (16 bit) accesses. Each CFR, with the

exception of the cycle timer register at 14h and the Phy access register at 24h, can be addressed on byte or

word boundaries. The possible configurations for the interface are shown in Table 3−1. The TSB12LV32 can

also be directly connected to the Motorola 68000 and ColdFire line of MC/MP. Table 3−2 defines the mapping

of the microcontroller interface pins between the TSB12LV32, the Motorola 68000 and the ColdFire

microprocessor.

Table 3−1. Microcontroller Interface Modes of Operation

TSB12LV32 MODE-CONFIGURATION TERMINALS

MODE OF OPERATION

COLDFIRE M8BIT_SIZ0 MCMODE_SIZ1

MODE OF OPERATION

0 0 0 16-bit fixed timing mode

0 0 1 16-bit MCS-MCA handshake mode

0 1 0 8-bit fixed timing mode

0 1 1 8-bit MCS-MCA handshake mode

1 0 0 ColdFire 4-byte (2-word) burst mode

1 0 1 ColdFire 2-byte (1-word) mode

1 1 0 ColdFire 1-byte mode (not supported)

1 1 1 ColdFire 16-byte (8-word) burst mode

Table 3−2. TSB12LV32 MP/MC Interface Terminal Function Matrix

TSB12LV32

MOTOROLA 68000/ColdFire MICROCONTROLLER

TERMINAL NAME USAGE TERMINAL NAME USAGE

MA0–MA6 Input A[6:0] Output

MD0–MD15 I/O D[31:16] I/O

MCA Output TAZ Input

MCS Input TSZ Output

MWR Input R/WZ Output

MCMODE/SIZ1, M8BIT/SIZ0 Input SIZ1, SIZ0 Output

TEA Output TEAZ Input

BCLK Input SCLK / CLK Input

The byte stacker allows the TSB12LV32 to be easily connected to most processors. The byte stacker consists

of a programmable 8-/16-bit data bus and a 7-bit address bus. The TSB12LV32 uses cycle-start and

cycle-acknowledge handshake signals to allow the local bus clock and the 1394 clock to be asynchronous

to one another. The TSB12LV32 has an interrupt driver to reduce cycling. All bus signal labeling on the

TSB12LV32 microcontroller interface uses bit 0 to denote the most significant bit (MSB).

The transfer error acknowledge (TEA

) is asserted whenever there is an illegal transfer request by the

microcontroller, such as:

ColdFire is a trademark of Motorola, Inc.