Analog Devices adsp-2100 Manual page 149

Host Interface Port
HSEL is a host select which allows the host to enable or disable the HIP for
host data transfers.
HACK is a host acknowledge output for hosts that require an acknowledge
for handshaking.
HSIZE configures the bus size; the HIP can function in both 8-bit and 16-
bit modes. If the HIP is configured for an 8-bit host (HSIZE=1), data is
read from and written to the lower eight bits of a HIP data register and the
upper eight bits are zero-filled (on host writes) or tristated (on host reads).
BMODE determines whether booting occurs through the HIP or through
the memory interface pins.
HMD0 and HMD1 are mode pins that configure the address, data and
strobe pins, as shown in Table 7.2. HMD0 configures the bus strobes,
selecting either separate read and write strobes or a single read/write
select and a host data strobe. HMD1 configures the bus protocol, selecting
either separate address (3-bit) and data (16-bit) buses or a multiplexed 16-
bit address/data bus with address latch enable. The timings of each of the
four bus protocols are described later in this chapter.
HIP Read Strobe
HRD
HMD0=0 HIP Write Strobe
HWR
HD15-0 HIP Data
HA2-0 HIP Address
HRW HIP Read/Write Select
HMD0=1 HIP Data Strobe
HDS
HD15-0 HIP Data
HA2-0 HIP Address
Table 7.2 HIP Configuration Modes
HMD1=0 HMD1=1
HIP Read Strobe
HRD
HIP Write Strobe
HWR
HAD15-0 HIP Address/Data
ALE HIP Address Latch Enable
HRW HIP Read/Write Select
HIP Data Strobe
HDS
HAD15-0 HIP Address/Data
ALE HIP Address Latch Enable
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