ACE9050
16
Bits
[7: 4]
[3: 2]
[1: 0]
Value
XXXX
00
01
10
11
00
01
10
11
Not used
Clock Control mode
SCI disabled
Use processor Clk for Baud rate
Not used
Use ACE 9050 Baud rate generator
Speed Select (Bits 3: 2 = 01)
E416
E4128
E41024
E44096
Description
Table 18 RMCR Transfer Rate/Mode Control register
mode is fully supported by the ACE9050 6303. This mode is
entered by execution of the SLP instruction. Escape is via an
interrupt or reset .
Address, Data and Memory Control
The Address, Data and control lines from the ACE9050 6303
connect to a kernel which interfaces to the on chip bus structures.
The Bus Interface block provides suitable buffering to drive
required buses externally, and configure the I/0 for Emulation
mode.
Interrupt Processing
The interrupt processing in the ACE9050 6303 is essentially
the same as a generic 6303, the exception being NMI, which
is not available. The IRQN is internally connected to the I
2
C
interrupt, the External Interrupt and the Internal interrupt
blocks.
These blocks combine all the possible sources for interrupts
into one line which is connected to IRQN. This is also
connected to a pin for use in Emulation mode. The IRQN is
maskable. The interrupt mask bit in the Condition Code
Register must be zero for the CPU to respond to the Interrupt
request, as with a generic 6303.
The Interrupt Vector Memory map is shown in Table 20.
Error Processing
An interrupt is generated when an undefined op-code is
fetched, or when an instruction is fetched from an impossible
address. This is in the range 0000- 007F for the ACE9050 (0000001F for a standard 6303).
2. INTERNAL ROM BOOT BLOCK
The ROM code provides a boot block for the ACE9050.
Following a reset condition code execution will always start in the
internal ROM. The internal ROM data flow depends on the
condition of the SERV Input and thus the mode of operation of
the ACE9050. The operation flow of the IROM is shown in Fig.
12 and described in the following sections:
Normal Mode
1. Read serial data on ACEBus DTFG line
2. Configure ACE9030 Reference dividers via ACEBus.
3. Set the program counter to the beginning of external ROM
(1800H).
Service Mode
1. Read serial data on ACEBus DTFG line
2. Configure ACE9030 Reference Dividers via ACEBus
3. Configure the UART to RX
4. Wait 2 seconds for special code on UART - if not found go to
step 3 of Normal Mode
5. Load Data from UART into RAM
Bits
[7:0] (Data)
[7:0] (Data)
RDR: Received Data Register
Read received bits. First bit received is
placed in bit 0, last in bit 7
TDR: Transmit Data Register
Write register to store bits before serial
transfer from Transmit shift register, bit 0 first
Description
Table 19 Receive and Transmit Data registers
In Normal Mode the SCI should be initialised before operation.
This means writing to the mode select and the control/status
register. In Service Mode the SCI is configured for 9600 baud,
and the receive interrupt enabled. When the transmitter is first
initialised it will send a ten-bit preamble of ‘1’s before being ready
to transmit data.
Once initialisation is complete data transmission enabled by
writing to the transmit data register. TDRE is set to 0. A start bit
is transmitted (0). Next the eight bit data starting at bit0 are
transmitted followed by a single stop bit (1). The hardware sets
the TDRE bit in the TRCSR register. If the CPU does not transfer
another word the output goes high.
The receiver is configured during initialisation. If enabled and
a start bit is detected (0), the next nine bits will be sampled
approximately at the centre of each bit. If the ninth bit is a 1 the
data is transferred to the Receive data register. The RDFR bit is
set in the TRCSR register. If the ninth bit is not a 1 or the receive
data register is full then the ORFE bit is set to indicate an error.
A read of the TRCSR register followed by a read of the Received
data register (RDR) will clear these flags.
RAM Control Register (RAMCR)
This register is read only in the ACE9050. Bit 6 (RAME) is set
to zero: this is because the RAM on the ACE9050 is external to
the 6303 block. Bit 7 (STBY) is also set to zero by the ACE9050
because Standby mode is not supported.
Operating Modes
The Generic 6303R has two modes: Multiplexed and nonMultiplexed, where the mode is selected externally using P2[0],
P2[1] and P2[2]. This is not required on the ACE9050, where the
mode is set to mimic multiplexed internally when the reset (MRN)
is released . The ACE9050 processor has two fundamental
modes of operation: Emulation and Normal, which are described
in the MODES OF OPERATION section.
Low Power Consumption Modes
The generic 6303 Standby mode is not supported by the
ACE9050 6303. The STBY pin is not accessible. The Sleep
Priority
1
2
3
4
5
6
7
8
MSB
FFFE
FFEE
FFFA
FFF8
FFF6
FFF4
FFF2
FFF0
LSB
FFFF
FFEF
FFFB
FFF9
FFF7
FFF5
FFF3
FFF1
Interrupt
Vector
RES
TRAP
Software Interrupt (SWI)
IRQN
ICF (Timer Input Capture)
OCF (Timer OP Compare)
TOF (Timer Overflow)
SCI (UART)
Table 20 Interrupt vector memory map